Basic core material encapsulated in an inorganic shell suitable for use in a biological carrier material

Abstract

Described herein is a (e.g., hardenable dental) composition comprising (e.g., a first portion comprising) an encapsulated material, wherein the encapsulated material comprises a basic core material and an inorganic shell material comprising a metal oxide surrounding the core; and (e.g., a second portion comprising) water or an acidic component. Also described is an encapsulated material (e.g., suitable for use in a biological carrier material) comprising a basic core material and an inorganic shell material comprising a metal oxide surrounding the core.

Description

Background Technology

[0001] Various adhesives suitable for medical and dental applications have been described. See, for example, Mitra et al., US 5,154,762; WO2016 / 005822; and US2008 / 0058442. Summary of the Invention

[0002] In one embodiment, the hardenable dental composition is described as comprising: a first portion comprising an encapsulating material comprising an alkaline core material and an inorganic shell material comprising a metal oxide surrounding the core; and a second portion comprising water or an acidic component.

[0003] In a typical implementation, the composition initially has an acidic or neutral pH when the first and second parts are combined. The shell is capable of being degraded by the aqueous or acidic component of the second part. During shell degradation, the alkaline core material releases –OH groups, thereby increasing the pH.

[0004] In some embodiments, the alkaline core material is curable, such as in the case of calcium silicate. In some embodiments, the composition further comprises at least one second filler, such as fluoroaluminosilicate (FAS) glass and / or nanoparticle fillers. In some embodiments, the first and / or second portions comprise polymerizable materials.

[0005] In another embodiment, a composition is described comprising an encapsulating material comprising an alkaline core material and an inorganic shell material comprising a metal oxide surrounding the core; and water or an acidic component.

[0006] In another embodiment, the encapsulating material may be suitable for a biocarrier material comprising an alkaline core material and an inorganic shell material comprising a metal oxide surrounding the core. Curable (e.g., dental) compositions comprising encapsulated materials are also described. In some embodiments, the curable composition further comprises a second filler and / or a polymerizable material, as described herein. In some embodiments, the curable or curing composition comes into contact with water or an acidic component (e.g., a biofluid) during use.

[0007] The present invention also describes various methods of use, including providing a hardenable or hardening (e.g., curing) composition as described herein and applying the composition to a tooth or bone structure.

[0008] In some embodiments, the composition comprises a polymerizable material, and the method further includes curing the composition by contacting it with a radiation source. Curable or hardening (e.g., solidifying) compositions can provide various technical effects, such as delayed release of alkaline core materials, delayed increase in alkalinity, promotion of remineralization of tooth or bone structures, and increased average ALP activity in pulp cells. In some embodiments, the composition is a dental adhesive or cement for bonding dental articles to tooth structures. In other embodiments, the composition is a dental restorative. Detailed Implementation

[0009] The material described here is an encapsulating material. This encapsulating material is suitable for use in biological carrier materials, such as hardenable dental compositions. The encapsulating material comprises a chemically alkaline core material and an inorganic shell material surrounding the core. The shell material and the thickness of the shell can be selected to allow for controlled and / or delayed release or reaction of the alkaline core material. In some embodiments, the release of the alkaline core material is used to increase alkalinity after a delayed time period.

[0010] Encapsulating fillers contain basic core materials. The basic core material and the materials forming the core (e.g., compounds) are typically solid at 25°C.

[0011] The alkaline core can be a single particle or a collection of smaller associated particles. As used herein, the term "associated" refers to a collection of two or more primary particles that are aggregated and / or agglomerated. Similarly, the term "non-associated" refers to a collection of two or more primary particles that are not aggregated and / or agglomerated.

[0012] In some implementations, the alkaline core may comprise multiple aggregated particles. The term "aggregate" or "aggregated" refers to strong association between primary particles. For example, primary particles may be chemically bonded to each other. The breakdown of aggregates into smaller particles (e.g., primary particles) typically does not occur during the fabrication of the core material and its encapsulation, thus keeping the aggregated core particles as aggregates. Similarly, the term "non-aggregated" refers to primary particles that do not exhibit strong association with other primary particles.

[0013] In other embodiments, the alkaline core may comprise multiple agglomerated particles. As used herein, the term "agglomerated" or "agglomerated" refers to weak association between primary particles. For example, primary particles may be held together by charge or polarity. The agglomeration may break down into smaller particles (e.g., primary particles) during the manufacture of the core material and its encapsulation. Similarly, the term "non-agglomerated" refers to primary particles that do not exhibit weak association with other primary particles.

[0014] The average (e.g., primary, associated, or agglomerated) particle size of the core is typically at least 0.2 micrometers, 0.5 micrometers, 1 micrometer, 2 micrometers, 3 micrometers, 4 micrometers, or 5 micrometers and typically no greater than 1 mm, 750 micrometers, or 500 micrometers, as measured using, for example, a sedimentation analyzer. In some embodiments, such as in the case of curable dental compositions, the basic core material typically has an average (e.g., primary, associated, or agglomerated) particle size no greater than 250 micrometers, 200 micrometers, 150 micrometers, 100 micrometers, or 50 micrometers. Because the shell is typically thin, the encapsulating material may also fall within the average particle size just described.

[0015] The core material is alkaline. Chemically alkaline materials are those that donate electrons, accept protons, and typically provide hydroxyl ions in aqueous solutions.

[0016] The core of the encapsulated material is considered alkaline if it has or exhibits one or more of the following properties: including containing a sufficient amount of a high pKa component, providing an alkaline pH when added to deionized water (as described in further examples) or providing an alkaline pH when added to an acidic buffer (as described in further examples).

[0017] Basic materials are used to react with acids and acidic buffer solutions, thereby increasing the pH. The change in pH and the rate of pH change depend on the strength of the basic component within the core material, the chemical and physical form of the basic component, and the amount of the basic component.

[0018] In some embodiments, the core of the encapsulating material is strongly basic. Strongly basic materials include, and are prepared from, a sufficient amount of a strongly basic material (e.g., a compound) typically having a pKa in the range of about 11-14. Examples of strongly basic compounds include oxides and hydroxides of alkali metals and alkaline earth metals, as well as strongly basic salts such as alkali metal phosphates. Specific examples of strongly basic core compounds include oxides and hydroxides of Na, K, Ca, Sr, and Ba; silicates of Na, K, Ca, Sr, and Ba; and aluminates of Na, K, Ca, Sr, and Ba. Strongly basic silicates and glasses typically contain at least 1, 2, or 3 moles of a strongly basic core compound (e.g., CaO) per mole of silica based on cation moles. Similarly, strongly basic aluminates typically contain at least 1, 2, or 3 moles of a strongly basic core compound (e.g., CaO) per mole of aluminate based on cation moles.

[0019] In some embodiments, the strongly basic material may be a heterogeneous physical mixture of at least one strongly basic compound and a less basic or neutral material. For example, the strongly basic material may be a physical mixture of silica and sodium hydroxide. Sodium hydroxide is a strongly basic material having a pKa of 13.8. A 0.1N aqueous solution of sodium hydroxide has a pH of 13. By weight percentage, one gram of a mixture of 96 wt% silica and 4 wt% sodium hydroxide in one liter of water will provide a 0.1N aqueous solution of sodium hydroxide. When the encapsulating material is a physical mixture, substantially all strongly basic compounds are accessible during shell degradation. Therefore, in this embodiment, the alkaline core material may contain a small amount (e.g., at least 1 wt%, 2 wt%, or 3 wt%) of a strongly alkaline material to provide a delayed pH of at least 8.5 or 9 in deionized water (according to the test method described in the examples). However, higher concentrations of chemically alkaline core material may be required to provide a delayed pH of at least 8.5 or 9 in acidic buffer solutions. For example, depending on the pKa of the strongly alkaline material, the amount of the strongly alkaline material may be 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, or 10 wt% of the total encapsulated material.

[0020] In other embodiments, the core of the encapsulated material is a multi-component crystalline compound comprising and prepared therefrom at least one strongly basic material (e.g., a compound) and other components (such as alkaline earth metal silicates). In other embodiments, the core of the encapsulated material may be characterized as a multi-component amorphous glass prepared from at least one strongly basic material (e.g., a compound). The strongly basic material (e.g., the compound) may be uniformly or non-uniformly distributed in the glass structure. When the core of the encapsulated material is a molten multi-component material such as glass, the concentration of the strongly basic compound (which can be determined by X-ray fluorescence (XRF) or inductively coupled plasma (ICP)) is typically at least 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, or 50 wt%, and at most 75 wt%, based on the total basicity of the core material.

[0021] In some advantageous embodiments, the core comprises and is prepared from CaO having a pKa of 11.6. CaO can be used to provide both a delayed increase in pH and a source of calcium ions. The amount of CaO is typically at least 5 wt%, 10 wt%, 15 wt%, 20 wt%, or 25 wt%, and the amount of Ca can be about 71% of such values ​​in a range of up to 75 wt% or greater.

[0022] Specific examples of strongly basic multicomponent core materials containing CaO include Portland adhesive (reported to contain 60-70 wt% CaO); tricalcium silicate (containing approximately 75 wt% CaO); and bioactive glass, such as that available from 3M Advanced Material Division (containing approximately 25 wt% CaO and approximately 25 wt% Na2O).

[0023] In other embodiments, the core of the encapsulating material is weakly basic. The weakly basic material comprises at least one material (e.g., a compound) having a significant amount of at least one material having a pKa in the range of at least 8 but less than 11. Examples of weakly basic cores include oxides of Cu, Zn, and Fe, as well as weakly basic salts such as NaF, calcium acetate, and hydrogen phosphate.

[0024] Alternatively, the weakly basic core material may contain a small amount of a strongly basic compound or be prepared from it. A weakly basic core material alone typically cannot provide a sufficient amount of hydroxyl ions to adequately increase the pH of an acidic solution. However, a weakly basic core material alone can provide a sufficient amount of hydroxyl ions to adequately increase the pH of water. Furthermore, encapsulated weakly basic core materials can be used in combination with encapsulated strongly basic core materials.

[0025] Encapsulated alkaline materials are typically not reducing agents in redox curing systems. In some advantageous curable materials (e.g., dental or medical), a beneficial technical effect is the control of pH, ensuring the composition is initially acidic for a sufficient amount of time to promote adhesion, and then changes to alkalinity to promote remineralization. This pH change is sufficiently delayed so that it occurs after curing. Encapsulation of a reducing agent will delay the redox curing reaction. Furthermore, since the reducing agent is typically a weak base used in relatively low concentrations, encapsulating the reducing agent alone will not provide the desired increase in pH.

[0026] In an advantageous embodiment, the core material further comprises and is prepared from one or more neutral compounds defined herein as having a pKa of at least 6, 6.5, or 7 and less than 8. In some embodiments, such neutral compounds exhibit low solubility in deionized water, and / or weak acid solutions, and / or weak base solutions. Weak acid solutions typically have a pH less than 7 but greater than 4. Weak base solutions typically have a pH greater than 7 but less than 10. Low solubility is defined as dissolving in less than 100 g / L (i.e., 10% by weight). In some embodiments, dissolving in less than 50 g, 25 g, 5 g, or 1 g per liter. Neutral compounds include, for example, silica, zirconium oxide, titanium dioxide, alumina, and combinations thereof. While a pKa greater than 7 indicates slightly basicity, such basicity is less than that of weakly basic core materials and significantly less than that of strongly basic core materials as described above.

[0027] When the core material contains an alkaline material (e.g., one or more compounds or a combination of an alkaline material and a neutral material), the alkalinity of the core material can be estimated based on the weight of the components. Therefore, the core material contains the amount of alkaline material (e.g., compounds) as described above.

[0028] However, when the core material also contains acidic substances (e.g., compounds), alkalinity becomes more difficult to estimate. Especially for embodiments where it is difficult to estimate the alkalinity of the core material based on its composition or compositional analysis, the alkalinity of the core material or encapsulated core material can be defined by the pH change of a specified amount of material in deionized water or an acidic solution (e.g., a buffer solution). These tests can also be used to verify that the core material or encapsulated core material is indeed alkaline.

[0029] For example, fluoroaluminosilicate (FAS) glass is a homogeneous glass structure prepared from approximately 19 wt% of a strongly basic compound (SrO), with the remainder prepared from neutral (SiO2) and other compounds. Referring to Table 11, when tested in deionized water according to the test method described in the examples, the FAS glass lowers the pH to 15 within 6.5 minutes and is therefore considered a weakly acidic core material.

[0030] In some implementations, the alkalinity of the core material or encapsulated core material can be determined by the pH change of a specified amount (0.25 g) of material in 25 g of deionized water. Unencapsulated core materials typically change the pH of deionized water from neutral to at least 8.5 or 9. This typically occurs within 1, 2, 3, 4, or 5 minutes, but can take up to an hour or 24 hours. For example, referring to Table 10, unencapsulated (e.g., bioactive glass) core materials can provide a pH of 10 in water within 20 seconds. The same encapsulated core material requires a longer time to provide such a pH because the core material cannot release hydroxyl ions until the inorganic shell material has been sufficiently degraded, such as through dissolution. However, even with encapsulated materials, rapid but small pH changes can occur in DI water if a small fraction of the material is unencapsulated or less encapsulated than the majority of the sample.

[0031] In an advantageous embodiment, the alkalinity of the core material or encapsulating material can be determined by the pH change of a specified amount (0.25 g) of the material in a buffer solution having a pH of 4 (e.g., buffer solution BDH5018), which is a solution of 15 g of deionized water and 10 g of an aqueous potassium hydrogen phthalate buffer solution, wherein the solution is adjusted to pH 4.00 at 25°C (with hydrochloric acid). This test is referred to herein as a “buffer test.” When a strongly alkaline core material or encapsulating material undergoes a buffer test, it can also reach a pH of at least 8.5 or 9. It should be understood that a larger amount of hydroxyl ions is required to change an acidic solution to an alkaline pH compared to deionized water. Therefore, this pH change can take longer compared to the same material in deionized water. In some embodiments, such a pH change occurs within 5, 10, or 15 minutes, but can take up to 1 hour or 24 hours. The same encapsulated core material takes longer to provide such pH changes because it cannot release hydroxyl ions that react with acid until the inorganic shell material has been sufficiently degraded, such as through dissolution and / or decomposition. In one embodiment, referring to Table 8, the unencapsulated (e.g., bioactive glass) core material reaches pH 8.5 within 15 minutes and pH 9 within 40 minutes according to the buffer test. The same encapsulated (e.g., bioactive glass) core material reaches pH 8.5 within 35 minutes according to the buffer test, and the pH continues to rise after 1 hour.

[0032] When tested according to the buffer test, the weakly basic core material can provide a small increase in pH. For example, the pH can change from 4 to 5. However, when tested according to the buffer test, the weakly basic core material does not provide enough hydroxyl ions to achieve a pH of at least 8.5 or 9.

[0033] Therefore, when the encapsulated alkaline core material is initially added to the water or buffer solution (i.e., immediately after the material is immersed in water or a buffer solution), it does not change the pH, but the pH subsequently increases at different rates depending on the shell and the alkaline core material.

[0034] In some embodiments, the alkaline core material is curable or self-curing when mixed with water, such as in the case of various neutral and synthetic adhesives. Conventional natural adhesives (e.g., Portland) and synthetic adhesives typically contain a large amount of calcium silicate (e.g., 3CaO-SiO2, 2CaO-SiO2), alone or in combination with one or more calcium aluminates (e.g., 3CaO-Al2O3, 4CaO-Al2O3-Fe2O3). When the alkaline core material is curable or self-curing, such an alkaline core material can be the only curable material in the curable composition. Thus, the first portion of the composition may contain 100% encapsulated alkaline core material.

[0035] Water-based medical and dental adhesives, such as those described in U.S. Patent 5,154,762 to Mitra et al., typically do not contain significant amounts of calcium silicate. Instead, such compositions typically contain particulate materials that can be characterized as acid-reactive metal oxides or acid-reactive glass fillers (e.g., FAS glass). These types of fillers are not self-curing when mixed with water. However, such acid-reactive fillers can be combined with multifunctional acidic components to provide curable materials.

[0036] In some implementations, the encapsulating material is an encapsulating (e.g., dental) filler.

[0037] Encapsulation (e.g., dental) fillers may contain a significant amount of neutral metal oxides having low solubility in water or acidic solutions with a pH of 3-4, as previously described. Neutral metal oxides include, for example, silica, zirconium oxide, titanium dioxide, and alumina. The amount of one or more metal oxides may range from 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt%, up to a maximum of 50 wt%, 60 wt%, 70 wt%, 80 wt%, or 90 wt% of the total weight of the basic core material. Encapsulated calcium silicate can also be characterized as a filler due to its silica content.

[0038] Hardenable dental compositions or other suitable (e.g., biological) carrier materials contain materials that promote remineralization, such as materials that release calcium ions, phosphorus-containing ions (e.g., phosphates), fluoride ions, or combinations thereof. These materials may be present in the core of an encapsulated filler, may be provided as a second filler such as FAS glass, or may be provided as a separate component in the hardenable dental composition.

[0039] In some embodiments, the core of the encapsulating (e.g., filler) material preferably comprises a material that promotes remineralization, such as a material that releases calcium ions, phosphate ions, fluoride ions, or combinations thereof. CaO can be used as both a highly basic material (e.g., a compound) and a source of calcium ions as described above. If the basic core material comprises a strongly basic material that does not release calcium ions, the core may also comprise another calcium material, such as a calcium salt (e.g., calcium glycerophosphate).

[0040] In some embodiments, the core of the encapsulated (e.g., dental) filler further comprises and is prepared from a material that promotes remineralization through the release of fluoride ions. In other embodiments, the (e.g., dental) composition further comprises a second filler comprising a material that promotes remineralization through the release of fluoride ions. The core or second filler material comprises and is prepared from fluorides such as AlF3, Na2AlF3, and mixtures thereof, in an amount ranging from 5% to 40% by weight. In some embodiments, the amount of AlF3 ranges from 10% to 30% by weight of the core or second filler material. In some embodiments, Na2AlF3 ranges from 2% to 10% by weight of the core or second filler material.

[0041] In some embodiments, the core of the encapsulated (e.g., dental) filler further comprises a material that promotes remineralization through the release of phosphate ions. In other embodiments, the (e.g., dental) composition further comprises a second filler containing a material that promotes remineralization through the release of fluoride ions. In some embodiments, the core or second filler material comprises phosphides such as P2O5, AlPO4, and mixtures thereof, in an amount ranging from 2% to 25% by weight. In some embodiments, the amount of P2O5 ranges from 2% to 15% by weight of the core or second filler material. In some embodiments, the amount of AlPO4 ranges from 2% to 10% by weight of the core or second filler material.

[0042] The alkaline core can be encapsulated in an inorganic shell containing metal oxides using any suitable method, such as vapor deposition, atomic layer deposition (ALD), sputtering, or evaporation (these are techniques well known in the art).

[0043] In some embodiments, the method of preparing the encapsulated material includes providing an alkaline core material as described above, and encapsulating the alkaline core particles with an inorganic coating (e.g., continuous, non-particulate) using at least one vapor deposition technique. Vapor deposition techniques include chemical vapor deposition (CVD) such as atmospheric pressure chemical vapor deposition (APCVD), hydrolytic CVD, and plasma CVD.

[0044] Advantages of vapor deposition techniques used to provide coatings include that the coatings consist of molecular-scale materials without interference from solvents or liquid media. Some coating methods (e.g., ALD and CVD) tend to provide coatings consisting of conformal layers on irregular materials (e.g., powders or porous microparticles).

[0045] ALD and CVD are coating processes involving chemical reactions, in which the chemical reactants used are called chemical precursors. That is, they are precursors (i.e., coating precursors) to the material to be coated (e.g., a metal oxide coating). In some embodiments, a single coating precursor is used, while in other embodiments, at least two coating precursors are used. At least one coating precursor contains at least one metal cation required for the coating (e.g., a metal oxide coating).

[0046] A single coating precursor may be used when simple decomposition of the precursor (e.g., thermal decomposition or plasma-enhanced decomposition) is sufficient to form a coating. At least two coating precursors (e.g., metal oxide precursors) are used when at least one coating precursor contains at least one metal cation and chemically reacts with at least one additional precursor (i.e., a co-reactant) to form a coating (e.g., a metal oxide coating). The additional coating precursor is a co-reactant of the coating precursor containing at least one metal cation. One or more co-reactants chemically react with a coating precursor containing at least one metal cation to form a coating.

[0047] ALD coatings are typically deposited as a single monolayer via alternating pulses of a chemical precursor (e.g., a coating precursor containing at least one metal cation), absorption of a monolayer of the precursor, removal of excess precursor, and pulsed delivery of a co-reactant (e.g., a co-reactant containing at least one metal cation of the coating precursor). In this way, these coatings tend to be conformal and uniform. Alternatively, for example, the ALD system can additionally deposit thicker, non-self-limiting coatings, wherein absorption into the substrate is significantly greater than that of each chemical reactant monolayer during each pulse or cycle, resulting in a much larger amount of coating deposition.

[0048] CVD coatings may involve similar chemical reactions, but the precursors are typically supplied simultaneously and continuously. Uniformity can be enhanced by the continuous mixing of the powders being coated.

[0049] An effective coating method for preparing the particles described herein is atmospheric pressure CVD (APCVD). APCVD can be carried out in simple equipment, such as glassware. In some embodiments, a hydrolysis reaction is used to form (e.g., continuous) metal oxide coatings at temperatures ranging from room temperature (in the range of about 22°C) to about 180°C.

[0050] Exemplary precursors for ALD and CVD processes include coating precursors containing at least one metal cation (e.g., metal oxide precursors), such as alkyl metals (e.g., trimethylaluminum or triethylaluminum, diethylzinc), volatile metal chlorides (titanium tetrachloride, silicon tetrachloride, aluminum trichloride), silanes, metal alkoxides (titanium isopropoxide, aluminum isopropoxide, silicon ethoxide), compounds having mixed alkyl, halide, hydride, alkoxy, and other groups, and other volatile organometallic compounds. Exemplary co-reactants for coating precursors containing at least one metal cation (e.g., metal oxide precursors containing at least one metal cation) include water, oxygen, ozone, ammonia, and alkylamines. In addition to metal oxides, other inorganic non-metallic coating materials are deposited using a chemical reaction between the coating precursor and its co-reactant (e.g., a metal nitride coating deposited using a metal nitride precursor containing at least one metal cation and its co-reactant).

[0051] Exemplary (e.g., continuous) coatings comprise, for example, non-metallic inorganic materials, such as metal oxides (e.g., Al, Si, Ti, Zr, Mg, and Zn). In some embodiments, the shell material comprises at least 50 wt%, 60 wt%, 70 wt%, 80 wt%, 90 wt%, or 100 wt% of a single metal oxide or a combination thereof. Exemplary metal oxides include forms such as hydroxides and hydrated oxides, as well as forms having mixed anions (e.g., oxide halides, hydroxyl groups, small amounts of alkyl groups, or carboxylate groups, etc.). The shell material is primarily an inorganic material having a carbon content of no more than 20 wt%, 10 wt%, 5 wt%, or 1 wt%. Furthermore, the encapsulated alkaline material may also have a carbon content of no more than 20 wt%, 10 wt%, 5 wt%, or 1 wt%. The shell material may also comprise metal nitrides, metal sulfides, metal oxysulfides, and metal oxynitrides. The coating can be amorphous, crystalline, or mixed, single-phase or multiphase, and can contain one or more cations and one or more anions. In some embodiments, the coating is an amorphous alumina with or without some hydroxyl groups or bound water.

[0052] The shell material may be a weakly alkaline material. However, the alkalinity of the shell material is insufficient to produce the desired pH change, especially according to the previously described buffer test or disk buffer test (as described later).

[0053] In some embodiments, the encapsulation of alkaline particles with a continuous coating is accomplished via an APCVD coating process, wherein the alumina-based coating is provided using trimethylaluminum (TMA) and water. The precursors are introduced into the reaction chamber via a bubbler that flows a carrier gas through each liquid precursor. Generally, as is typical for CVD processes, carrier gases carrying each component are delivered to the reaction chamber simultaneously and continuously. The desired flow rates and ratios can be adjusted to produce coatings with the desired quantity and properties. In some embodiments, the trimethylaluminum (TMA) flow rate and the water flow rate are independently set at at least 50 cm⁻¹. 3 / min or 100cm 3 / min to 1000cm 3 / min, 1500cm 3 / min or 2000cm 3 The flow rate is typically within the range of / min. The water flow rate is generally 2 to 10 times higher than the TMA flow rate, or even higher. In some embodiments, the flow of any precursor can be initiated or maintained independently for a period of time in which no other precursor flows. In some embodiments, the flow of the precursor can be changed or adjusted once or multiple times throughout the process.

[0054] In some embodiments, the initial ratio of the co-reactant (e.g., water) to the coating precursor containing at least one metal cation (e.g., TMA) is higher than the ratio later in the process. In other embodiments, the initial ratio of the co-reactant (e.g., water) to the coating precursor containing at least one metal cation is lower than the ratio later in the process. In some embodiments, the composite particles are contacted only with the co-reactant (e.g., water) for an initial period of time before contacting the coating precursor containing at least one metal cation. In some embodiments, the composite particles are contacted only with the coating precursor containing at least one metal cation before contacting the second reactant (e.g., the co-reactant of the coating precursor). In some embodiments, the different flow conditions are maintained for at least 5 minutes (or in other embodiments, at least 10 minutes, 15 minutes, 20 minutes, 30 minutes, 45 minutes, 60 minutes, or 90 minutes), and up to 150 minutes.

[0055] In some embodiments, a coating of a first composition is deposited, followed by the deposition of a coating of a second composition. For example, an alumina-based coating may be deposited by TMA and water, followed by a titanium dioxide-based coating deposited by TiCl4 and water.

[0056] In some embodiments, the shell, or in other words, the sealant, has an average thickness of at least 5 nm, 10 nm, 15 nm, 20 nm, or 25 nm. The shell thickness can range from up to 250 nm, 500 nm, 750 nm, or 1000 nm (1 micrometer). In some embodiments, such as in the case of encapsulated dental fillers, the shell thickness is typically in the range of up to 100 nm, 150 nm, or 200 nm.

[0057] Based on weight percent, the shell material is typically at least 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, or 0.5 wt% of the total encapsulated material. The amount of shell material, expressed as a percentage by weight, may range from a maximum of 15 wt% or 20 wt% of the total encapsulated material, but more typically not greater than 10 wt%, 9 wt%, 8 wt%, 7 wt%, 6 wt%, or 5 wt%.

[0058] In a preferred embodiment, the shell material and shell thickness are selected to enable controlled and / or delayed release or reaction of the alkaline core material.

[0059] In a preferred embodiment, the shell is initially impermeable (i.e., the materials from the composition and the core material cannot interact through the shell via simple diffusion). Interactions occur after the shell is altered by interaction with other materials (e.g., degrading, corroding, or dissolving). Compositions (e.g., two-part compositions) containing components that degrade the shell, such as water or acid, can be designed. In other embodiments, shell degradation can occur due to contact with water or acidic components during use. In this embodiment, the source or water or acidic component can be a biological fluid (e.g., saliva or water retained in soft tissue surrounding teeth or bone).

[0060] Referring to Tables 4-7 of the embodiments described later, in one embodiment, the unencapsulated (e.g., Portland adhesive or tricalcium silicate) alkaline material provides an alkaline pH (e.g., at least 8.5, 9, 9.5, 10, or 10.5) within 1 minute when subjected to the aforementioned buffer test. However, according to the buffer test, the encapsulated (e.g., Portland adhesive or tricalcium silicate) alkaline material does not provide an alkaline pH (e.g., at least 8.5, 9, 9.5, 10, or 10.5) for 2 minutes, 3 minutes, 4 minutes, 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes, or 10 minutes or longer. In some embodiments, the encapsulated (e.g., Portland adhesive) alkaline material does not provide an alkaline pH (e.g., at least 8.5, 9, 9.5, 10, or 10.5) for 15 minutes, 20 minutes, 25 minutes, 30 minutes, 35 minutes, 40 minutes, or 45 minutes. In some implementations, the encapsulated (e.g., Portland adhesive) alkaline material does not provide an alkaline pH (e.g., at least 8.5, 9, 9.5, 10, or 10.5) for 100, 200, or 300 minutes.

[0061] Referring to Table 8 of the embodiments described later, in another embodiment, the unencapsulated (e.g., bioactive glass) alkaline material provides an alkaline pH (e.g., at least 8.5, 9, 9.5, 10, or 10.5) within 5 minutes when subjected to the aforementioned buffer test. However, according to the buffer test, the encapsulated (e.g., bioactive glass) alkaline material does not provide an alkaline pH (e.g., at least 8.5, 9, 9.5, 10, or 10.5) for 30-40 minutes.

[0062] Referring to Table 9 of the embodiments described later, in another embodiment, an unencapsulated (e.g., Portland adhesive) alkaline material provides an alkaline pH of 11.5 within 20 seconds when tested in deionized water. However, an encapsulated (e.g., Portland adhesive) alkaline material provides an alkaline pH of at least 8.5 within 20 seconds when tested in deionized water. Referring to Table 10 of the embodiments described later, in another embodiment, an unencapsulated (e.g., bioactive glass) alkaline material provides an alkaline pH of 10.5 within 20 seconds when tested in deionized water. However, an encapsulated (e.g., bioactive glass) alkaline material provides a pH of at least 9.8 within 20 seconds. Therefore, pH changes in acidic (e.g., buffer solutions) solutions can occur at a significantly slower rate than in deionized water.

[0063] In a preferred embodiment, the delayed release or reaction of the alkaline core material is used to increase the alkalinity of the (e.g., biological) carrier material, such as a hardenable dental material, at a later time, such as after application to the tooth or bone structure and typically after curing. Unencapsulated alkaline materials can produce a desiredly large (but not undesirably rapid) increase in pH. The same encapsulated alkaline material can produce a desired increase in pH, but after a longer duration.

[0064] The alkalinity of a carrier material (e.g., biological) such as a hardenable (e.g., dental) composition (containing an encapsulated alkaline material) can be assessed by measuring the pH change of a disc (3.1 mm by 3.1 mm high) of hardened (i.e., cured) material immersed in 1.5 ml of 10 mM Na₂HPO₄ (commonly known as PBS) buffer solution contained in a 2 ml plastic centrifuge tube. The PBS buffer solution can be prepared by dissolving 8 g NaCl, 0.2 g KCl, 1.44 g Na₂HPO₄, and 0.24 g KH₂PO₄ in 800 ml distilled H₂O, adjusting the pH to 7.4 with HCl, bringing the volume to 1 L with additional distilled water, and then autoclaving. This test will subsequently be referred to as the disc buffer test.

[0065] A representative two-part curable (e.g., dental) composition suitable for evaluating encapsulated (e.g., dental) basic materials comprises a first part as described below and a second part containing an encapsulated basic material. The first and second parts are combined (in a 1:1 weight ratio) and radiation cured as further described in the examples. In one embodiment, the second part comprises 65 wt% of the encapsulated basic material as described herein, 33.7 parts of hydroxyethyl methacrylate (HEMA), and 1 wt% of pyrolytic silica. In another embodiment, the second part comprises 33.7 parts of hydroxyethyl methacrylate (HEMA), 16.25 wt% to 65 wt% (e.g., 32.5 wt%) of the encapsulated basic material as described herein, 0 wt% to 32.5 wt% of FAS glass, and 1 wt% of pyrolytic silica.

[0066] The first part of the two-part curable composition .

[0067] Components Weight percentage of the composition (wt%) Hydroxyethyl methacrylate (HEMA) 12.07 Butylated hydroxytoluene (BHT) 0.03 Camphorquinone (CPQ) 0.33 Deionized water 22.01 VBP 25.83 Calcium glycerol phosphate 4.57 Zr / Si nanocluster filler 30.14 Ytterbium fluoride 5.02

[0068] In some embodiments, the concentration of the encapsulated alkaline material is typically at least 2 wt%, 3 wt%, 4 wt%, 5 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt%, 55 wt%, 60 wt%, or 65 wt%, up to a maximum of 100 wt%, of the second portion of the curable (e.g., dental) composition. The total curable (e.g., dental) composition contains half of this concentration of encapsulated alkaline material. Therefore, the concentration of the encapsulated alkaline material is typically at least 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 5 wt%, 7.5 wt%, 10 wt%, 12.5 wt%, 15 wt%, 17.5 wt%, 20 wt%, 22.5 wt%, 25 wt%, 27.5 wt%, 30 wt%, or 32.5 wt%, up to a maximum of 50 wt%, of the total curable (e.g., dental) composition. Although the formulation with 16.25% by weight of bioactive glass in Part II (8% by weight of the total) exhibited marginal performance, it is speculated that the concentration of highly alkaline materials (CaO, Na2O) in the bioactive glass could be increased so that a smaller concentration could provide a delayed increase in pH of at least 8.5 or 9.

[0069] Referring to Tables 12-22 of the embodiments described later, in one embodiment, for a composition comprising more than 16.25% by weight of an encapsulated alkaline material, the encapsulated alkaline material provides an alkaline pH (e.g., at least 8.5, 9, 9.5, 10, or 10.5) for 46 hours, 72 hours, 100 hours, 147 hours, 260 hours, 360 hours, or 500 hours.

[0070] Because it contains one or more acidic components for a sufficient duration to provide good adhesion to bone or tooth structures, hardenable (e.g., dental) compositions are typically acidic (pH 1, 2, 3, 4, 5, or 6) before curing. This time period can vary to some extent, but is initially acidic (immediately after immersion of the hardenable or curing composition in water or a buffer solution), and is typically acidic for at least 30 seconds, 1 minute, 2 minutes, 3 minutes, 4 minutes, or 5 minutes. In other embodiments, the hardenable or curing (e.g., dental) composition is initially neutral (pH 7-7.5), and alkalinity increases after different time periods ranging from 1 hour to 1 day (pH at least 8, 8.5, 9, 9.5, 10, 10.5, or 11), and in some embodiments, alkalinity increases for up to 2, 3, 4, 5, 6, or 7 days or more.

[0071] In some embodiments, the curable (e.g., dental) composition may be characterized as an adhesive having multiple curing modes. In some embodiments, the adhesive is cured via a first mechanism through an ionic reaction between an acid and an acid-reactive filler (e.g., FAS glass). The reaction of the encapsulated basic material (e.g., filler) is delayed as described above and therefore generally does not impair the curing reaction. The adhesive is also cured via a second mechanism through photo-initiated radical crosslinking via the olefinically unsaturated component. The adhesive may optionally be cured via a third mechanism through redox-initiated radical crosslinking of the olefinically unsaturated component.

[0072] These adhesives are typically formulated in two parts. The first part is usually a powder or liquid portion containing an encapsulated alkaline filler and an acid-reactive (e.g., FAS glass) filler for curing. The second part is usually an aqueous liquid portion containing an acidic polymer and water. In some cases, the encapsulating filler can be designed to provide controlled curing and a subsequent sustained pH rise.

[0073] The binder may optionally contain both a water-soluble reducing agent and a water-soluble oxidizing agent in separate portions. If the reducing agent is present in the liquid portion, the oxidizing agent is typically present in the powder portion, and vice versa. Suitable reducing agents include ascorbic acid, sulfinic acid, barbituric acid and its derivatives, cobalt(II) chloride, ferrous chloride, ferrous sulfate, hydrazine, hydroxylamine (depending on the choice of oxidizing agent), oxalic acid, thiourea, and salts of disulfite or sulfite anions. Suitable oxidizing agents are the same as described above.

[0074] The amounts of reducing agent and oxidizing agent are sufficient to provide the desired degree of polymerization of the olefinically unsaturated component. The amount of reducing agent, based on the total weight of the unset binder composition (including water), is typically at least 0.01% or 0.02% by weight, and at most 5%, 6%, 7%, 8%, 9%, or up to 10% by weight. The amount of oxidizing agent, based on the total weight of the unset binder composition (including water), is typically at least 0.01% or 0.02% by weight, and at most 5%, 6%, 7%, 8%, 9%, or up to 10% by weight.

[0075] Reducing or oxidizing agents can be encapsulated with polymers such as those described in U.S. Patent 5,154,762 to Mitra et al. When a curable (e.g., dental) composition is cured via free radical crosslinking initiated by the redox reaction of an olefinically unsaturated component, the composition contains a sufficient amount of oxidizing agent for the crosslinking reaction, which is not encapsulated within an inorganic shell containing a metal oxide. The curable (e.g., dental) composition may also contain an oxidizing agent encapsulated within an inorganic shell containing a metal oxide for the purpose of increasing pH over a duration.

[0076] Binders are not limited to two-part powder-liquid compositions. For example, single-part anhydrous formulations can be prepared. These can be sold in dry form and prepared for use by adding water. Alternatively, a two-part paste formulation can be prepared by adding a suitable polymerizable liquid that does not react with an encapsulated basic and / or additional acid-reactive (e.g., FAS glass) filler (e.g., 2-hydroxyethyl methacrylate or "HEMA") to the filler, resulting in a first paste. The acidic polymer described above is then combined with a suitable filler that does not react with the acidic polymer (e.g., crushed quartz) to obtain a second paste. Both pastes are prepared for use by stirring them together.

[0077] The adhesive contains water during use. Water may be present in the sold composition or added prior to use. The water may be distilled water, deionized water, or simply tap water. The amount of water is generally sufficient to provide suitable handling and mixing properties and to allow ion transfer during the filler-acid reaction. The amount of water is typically at least 1%, 2%, 3%, 4%, or 5% of the total weight of the adhesive (i.e., the first and second parts and any added water), and typically not more than 20% or 25%.

[0078] Adhesives are typically ion-curable, meaning they react via ionic reactions to produce hardened aggregates. Ionic reactions primarily occur between acidic groups on the polymer and acid-reactive (e.g., FAS glass) fillers.

[0079] In some embodiments, acid-reactive (FAS) glass is used in combination with an encapsulating alkaline (e.g., filler) material. In some embodiments, the amount of FAS glass is at least 5%, 10%, 15%, 20%, 25%, 30%, 35%, or 40% by weight of the first portion of the two-part composition, and up to about 50%, 55%, or 60% by weight. Since the first portion typically represents half of the total curable (e.g., dental) composition, the total concentration of acid-reactive (FAS) glass is half of the concentration just described. In addition to participating in ionic reactions, FAS glass also releases phosphorus and fluoride ions known to promote remineralization.

[0080] In some embodiments, the concentration of the acid-reactive (FAS) glass is greater than the concentration of the encapsulating basic (e.g., filler) material. In other embodiments, the concentration of the encapsulating basic (e.g., filler) material is greater than the concentration of the acid-reactive (FAS) glass. In some embodiments, in the second part of the two-part composition, the weight ratio of the encapsulated basic filler to the unencapsulated acid-reactive (FAS) glass is typically at least 1:1 or greater than 1:1, such as 1.5:1, 2:1, 2.5:1, 3:1, and at most 5:1, 6:1, 7:1, 8:1, 9:1, or 10:1.

[0081] The adhesive may also contain at least one olefinically unsaturated moiety. The olefinically unsaturated moiety may be present as a single component (e.g., as an acrylate-functionalized monomer or a methacrylate-functionalized monomer) or as a group on another component such as an acid polymer.

[0082] The olefinically unsaturated group is typically a terminal (e.g., terminal) radical polymerizable group containing a (meth)propylene group, such as (meth)acrylamidoyl (H₂C=CHCON- and H₂C=CH(CH₃)CON-) and (meth)acrylate (CH₂CHCOO- and CH₂C(CH₃)COO-). Other olefinically unsaturated polymerizable groups include vinyl (H₂C=C-) and vinyl ether (H₂C=CHO-). One or more terminally polymerizable olefinically unsaturated groups are preferably (meth)acrylate groups, especially for compositions cured by exposure to photochemical (e.g., ultraviolet or blue light) radiation. Furthermore, in curable dental compositions, methacrylate functional groups are generally preferred over acrylate functional groups.

[0083] In some embodiments, the olefinically unsaturated component is a water-miscible or water-soluble (meth)acrylate, such as 2-hydroxyethyl methacrylate, hydroxymethyl methacrylate, 2-hydroxypropyl methacrylate, tetrahydrofurfuryl methacrylate, glyceryl mono- or dimethacrylate, trimethylolpropane trimethacrylate, ethylene glycol dimethacrylate, polyethylene glycol (e.g., 400 and other molecular weights) dimethacrylate, urethane methacrylate, acrylamide, methacrylamide, methylenebisacrylamide or methylene methacrylate, and diacetone acrylamide, with methacrylamide being preferred. If desired, the olefinically unsaturated portion may be used. Preferably, the olefinically unsaturated portion exists as a group in the acidic polymer, as described in more detail below.

[0084] The second part contains an organic or inorganic acid component. In some embodiments, the acidic component is a polycarboxylic acid, such as poly(maleic acid) or poly(itaconic acid). In other embodiments, the acidic component is polyacrylic acid or phosphoric acid.

[0085] In some embodiments, the acidic component is an acidic polymer. Suitable acidic polymers include those listed in column 2, line 62 to column 3, line 6 of U.S. Patent 4,209,434. Preferred acidic polymers include homopolymers and copolymers of acrylic acids such as acrylic acid, itaconic acid, and maleic acid.

[0086] In some embodiments, the acidic polymer may be characterized as a photocurable ionomer, i.e., a polymer having side-attached ionic groups capable of undergoing a fixation reaction and side-attached free radical polymerizable groups, which enable the resulting mixture to polymerize upon contact with radiant energy, i.e., to cure.

[0087] As described, for example, in U.S. Patent 5,130,347, photocurable ionomers have the following general formula:

[0088] B(X) m (Y) n

[0089] in

[0090] B represents the organic backbone.

[0091] Each X is an independent ionic group.

[0092] Each Y is an independent photocurable group.

[0093] m is a number with an average value of 2 or higher, and

[0094] n is a number with an average value of 1 or higher.

[0095] Main chain B is preferably a carbon-carbon bonded oligomeric or polymeric backbone, which may optionally contain non-interfering substituents, such as oxygen, nitrogen, or sulfur heteroatoms. As used herein, the term "non-interfering" refers to substituents or linking groups that do not unduly interfere with the photocuring reaction of the photocurable ionomer.

[0096] The preferred X group is an acidic group, with a carboxyl group being particularly preferred.

[0097] Suitable Y groups include (but are not limited to) polymerizable olefinically unsaturated groups and polymerizable epoxy groups. olefinically unsaturated groups are preferred, especially those that can be polymerized by means of a free radical mechanism; examples of these are substituted and unsubstituted acrylates, methacrylates, alkenes, and acrylamides.

[0098] The X and Y groups can be attached to the main chain B directly or by means of any non-interfering organic linking group (such as substituted or unsubstituted alkyl, alkoxyalkyl, aryl, aryloxyalkyl, alkoxyaryl, arylalkyl, or alkylaryl).

[0099] Preferred photocurable ionomers are those in which each X is a carboxyl group and each Y is an olefinically unsaturated group, such as a (meth)acrylate group, which can be polymerized using a free radical mechanism. Such ionomers are typically produced by polymerizing polyolefins (e.g., formula B(X)). m+nThe photocurable ionomer is prepared by reacting a polymer (where each X is a carboxyl group) with a coupling compound containing both an olefinic unsaturated group and a group capable of reacting with a carboxylic acid group, such as an NCO group. The resulting photocurable ionomer preferably has at least one radically polymerizable group (e.g., a (meth)acrylate group) attached to the ionomer by means of an amide bond. The molecular weight of the resulting photocurable ionomer is typically between about 1000 g / mol and about 100,000 g / mol.

[0100] As determined using gel permeation chromatography and polystyrene standards, acidic polymers (e.g., photocurable ionomers) typically have a weight-average molecular weight of at least 5,000 g / mol and up to about 100,000 g / mol. In some embodiments, the acidic polymers (e.g., photocurable ionomers) have a molecular weight of less than 50,000 or 25,000 g / mol.

[0101] The concentration of the acidic component (such as a photocurable ionomer) is typically at least 5%, 6%, 7%, 8%, 9%, or 10% by weight of the first portion of the two-part composition, and typically no more than 30%, 25%, 20%, or 15% by weight. Since the first portion represents only half of the total curable (e.g., dental) composition, the total concentration of the acidic component (such as a photocurable ionomer) is approximately half of the concentration just described.

[0102] In some embodiments, the acidic component is a curable component in the form of an olefinically unsaturated compound having acid and / or acid precursor functional groups. Acid precursor functional groups include, for example, acid anhydrides, acyl halides, and pyrophosphates. Acid functional groups may include phosphate functional groups, phosphonic acid functional groups, sulfonic acid functional groups, or combinations thereof. Typically, when the composition contains a radiopaque filler comprising a basic surface, such as in the case of zirconia, the adhesive compositions described herein contain little (e.g., less than 10 wt%, 5 wt%, or 1 wt%) or no olefinically unsaturated compounds having carboxylic acid functional groups.

[0103] Alkenyl unsaturated compounds having acidic functional groups include, for example, α,β-unsaturated acidic compounds such as glyceryl phosphate mono(meth)acrylate, glyceryl phosphate di(meth)acrylate, hydroxyethyl methacrylate phosphate (e.g., HEMA-P), bis((meth)acryloyloxyethyl) phosphate, ((meth)acryloyloxypropyl) phosphate, bis((meth)acryloyloxypropyloxy) phosphate, (meth)acryloyloxyhexyl phosphate, bis((meth)acryloyloxyhexyl) phosphate (e.g., MHP), (meth)acryloyloxyoctyl phosphate, bis((meth)acryloyloxyoctyl) phosphate, (meth)acryloyloxydecyl phosphate, bis((meth)acryloyloxydecyl) phosphate, and caprolactone methacrylate phosphate.

[0104] In some embodiments, in addition to the encapsulating filler described herein, the composition (e.g., in dental applications) may also contain other (i.e., second) fillers. The second filler typically does not contain a (e.g., strongly) basic core material as described herein. The second filler typically contains a neutral metal oxide with low solubility as described above. The second filler may also be weakly basic or weakly acidic.

[0105] In some embodiments, the second packing material is an acid-reactive (FAS glass) packing material, as previously described.

[0106] In some embodiments, another filler comprises nanoparticles (e.g., inorganic metal oxides). These nanoparticles, or in other words, “nanoscale fillers,” can be used as viscosity and thixotropic modifiers. Such nanoparticles can also contribute in part to the mechanical properties of curable dental compositions. Due to their size, these nanoparticles also contribute to the refractive index of polymerizable resins.

[0107] In some embodiments, the inorganic oxide nanoparticles have a primary particle size of no more than 100 nm. Primary particle size typically refers to the size of discrete, non-aggregated particles. In other, less common embodiments, the nanoparticles may be aggregates of two or more types of (e.g., fused or covalently) bonded particles, wherein the aggregates have a particle size of no more than 100 nm. The average particle size can be determined by cutting a thin sample of the hardened dental composition and measuring the particle size of about 50-100 particles using a transmission electron microscope at 300,000 magnification and calculating the average value. The nanoparticles may have a single-peaked or multi-peaked (e.g., bimodal) particle size distribution. In some embodiments, the nanoparticles have an average particle size of at least about 2 nm, 3 nm, 4 nm, or 5 nm. In some embodiments, (e.g., zirconia) nanoparticles have an average particle size of no more than about 50 nm, 40 nm, 30 nm, 25 nm, 15 nm, or 10 nm.

[0108] Dental compositions may optionally include nanoparticles with a relatively low refractive index (e.g., inorganic metal oxides), such as silica. Including low-refractive-index nanoparticles reduces the refractive index of the polymerizable resin. Suitable silica nanoparticles are commercially available under the trade name NALCO COLLOIDAL SILICAS from Ecolab, Inc. (St. Paul, MN). For example, preferred silica particles are available using NALCO products 1034A, 1040, 1042, 1050, 1060, 2327, and 2329.

[0109] Silica particles are preferably made from aqueous colloidal dispersions of silica (i.e., sols or hydrogels). The concentration of colloidal silica in the silica sol is typically from about 1% to 50% by weight. Commercially available colloidal silica sols with different colloidal sizes are available; see Surface & Colloid Science, Vol. 6, ed. Matijevic, E., Wiley Interscience, 1973. Preferred silica sols for preparing fillers are supplied as dispersions of amorphous silica in aqueous media (such as Nalco colloidal silica manufactured by Ecolab) and those with low sodium concentrations that can be acidified by mixing with a suitable acid (e.g., Ludox colloidal silica manufactured by DuPont or Nalco 2326 from Ecolab).

[0110] In some embodiments, the dental composition comprises at least 0.5 wt%, 1 wt%, 1.5 wt%, or 2 wt% of low-refractive-index (e.g., silica) nanoparticles. The amount of low-refractive-index (e.g., silica) nanoparticles is typically no more than 30 wt%, 25 wt%, 20 wt%, 15 wt%, or 5 wt% of the dental composition. In other embodiments, the dental composition comprises less than 1 wt%, 0.5 wt%, 0.25 wt%, 0.1 wt%, or 0.005 wt% of low-refractive-index (e.g., silica) nanoparticles, or is substantially free of low-refractive-index (e.g., silica) nanoparticles.

[0111] When low-refractive-index (e.g., silica) nanoparticles are included in a dental composition, the concentration of low-refractive-index (e.g., silica) nanoparticles is typically lower than the concentration of high-refractive-index (e.g., zirconia) nanoparticles. Therefore, the weight or volume concentration of high-refractive-index (e.g., zirconia) nanoparticles is typically greater than the weight or volume concentration of low-refractive-index (e.g., silica) nanoparticles. In some embodiments, the weight or volume ratio of high-refractive-index (e.g., zirconia) nanoparticles to low-refractive-index (e.g., silica) nanoparticles is at least 1.1:1, 1.2:1, 1.3:1, 1.4:1, 1.5:1, 1.6:1, 1.7:1, 1.8:1, 1.9:1, or 2:1. In some embodiments, the weight or volume ratio of high-refractive-index (e.g., zirconia) nanoparticles to low-refractive-index (e.g., silica) nanoparticles is at least 2.1:1, 2.2:1, 2.3:1, or 2.4:1. In some embodiments, the weight or volume ratio of high-refractive-index (e.g., zirconium oxide) nanoparticles to low-refractive-index (e.g., silicon dioxide) nanoparticles is no greater than 100:1, 75:1, 50:1, 25:1, 10:1, or 5:1.

[0112] Suitable low-refractive-index (e.g., silica) nanoparticles and high-refractive-index (e.g., zirconia) nanoparticles are disclosed in U.S. Patents 6,387,981 (Zhang et al.) and 6,572,693 (Wu et al.), as well as PCT International Publications WO 01 / 30304 (Zhang et al.), WO 01 / 30305 (Zhang et al.), WO 01 / 30307 (Zhang et al.), WO 03 / 063804 (Wu et al.), U.S. Patents 7,090,721 (Craig et al.), 7,090,722 (Budd et al.), 7,156,911 (Kangas et al.), U.S. Patent 7,241,437 (Davidson et al.), and U.S. Patent 7,649,029 (Kolb et al.).

[0113] The dental compositions described herein preferably contain measurable amounts of inorganic metal oxide fillers. Fillers used in dental applications are typically ceramic in nature.

[0114] The filler can be selected from one or more of a variety of materials suitable for incorporation into compositions for dental applications, such as fillers currently used in dental composites and dental (e.g., crown) products. The filler is generally non-toxic and suitable for oral use. The filler can be radiopaque, radiopaque, or non-radiopaque. In some embodiments, the filler typically has a refractive index of at least 1.500, 1.510, 1.520, 1.530, or 1.540.

[0115] Commonly, it contains up to about 5% by weight of a component such as YbF3 to increase radiopaqueness. In some embodiments, the radiopaqueness of the cured dental composition is equivalent to that of 3 mm thick aluminum.

[0116] The filler can be either microparticles or fibers in nature. Microparticle fillers are typically defined as having an aspect ratio of 20:1 or less, more commonly 10:1 or less. Fibers are defined as having an aspect ratio greater than 20:1 or more commonly greater than 100:1. The shape of the particles can vary from spherical to ellipsoidal, or more planar, such as flakes or discs. Macroscopic properties can be highly dependent on the shape of the filler particles, especially the uniformity of the shape.

[0117] The dental compositions described herein include inorganic metal oxide filler materials that are larger in size than nanoparticles. As previously mentioned, nanoparticles are typically discrete, unaggregated particles with a particle size of no more than 100 nm. In contrast, inorganic metal oxide fillers are particulate or fibrous materials with at least one size greater than 100 nm, such as at least 150 nm or at least 200 nm. With regard to particulate fillers, the average particle size of the discrete unaggregated or aggregated particles is at least 200 nm. Inorganic metal oxide filler particles are highly effective in improving wear properties after curing.

[0118] In some embodiments, the filler may comprise a crosslinked organic material insoluble in the polymerizable resin, and may optionally be filled with an inorganic filler. Examples of suitable organic filler particles include filled or unfilled powdered polycarbonate, polyepoxide, poly(meth)acrylate, etc.

[0119] In some embodiments, the dental compositions described herein comprise non-acid-reactive fillers, such as quartz, pyrolytic silica, non-vitrified nanoparticles of the type described in U.S. Patent 4,503,169 (Randklev), and nanocluster fillers, such as those described in U.S. Patent 6,730,156 (Windisch et al.), U.S. Patent 6,572,693 (Wu et al.), and U.S. Patent 8,722,759 (Craig).

[0120] In some embodiments, the filler comprises nanoparticles in the form of nanoclusters, i.e., clusters of two or more associated by relatively weak but sufficient intermolecular forces that cause the particles to aggregate together, even when dispersed in a curable resin. Preferred nanoclusters may include loosely aggregated, generally amorphous clusters of non-heavy metal oxide (e.g., silica) particles and heavy metal oxide (i.e., having more than 28 atoms) such as zirconium oxide. Zirconia may be crystalline or amorphous. In some embodiments, zirconium oxide may be present as particles. The particles forming the nanoclusters preferably have an average diameter of less than about 100 nm. However, the average particle size of loosely aggregated nanoclusters is typically significantly larger.

[0121] In some embodiments, (e.g., dental) the composition further comprises a second filler comprising a neutral metal oxide, such as a zirconia / silica nanocluster filler. In both-part dental compositions, the filler comprising the neutral metal oxide is present in a substantial amount in the portion containing the first or second liquid. In some embodiments, a neutral or non-reactive filler is present in either or both of the acidic and non-acidic portions, while an acid-reactive filler (e.g., FAS glass) and / or an encapsulated basic core are present in the non-acidic portion and react with the acidic portion upon mixing.

[0122] In some embodiments, a first portion of the curable (e.g., dental) composition comprises a second filler comprising a neutral metal oxide, wherein the amount of such zirconia / silica nanoclusters is at least 5 wt%, 10 wt%, 15 wt%, or 20 wt%, and at most 30 wt%, 35 wt%, or 40 wt%. The total curable (e.g., dental) composition comprises about half such concentration of the second filler comprising a neutral metal oxide (such as zirconia / silica nanoclusters).

[0123] In some embodiments, the second packing material may also be encapsulated with a shell material containing metal oxides, as described in US 7,396,862.

[0124] A mixture of fillers can also be used.

[0125] In a typical embodiment, the second filler may include a surface treatment to enhance the adhesion between the nanoparticles and inorganic oxide fillers and the resin. Various surface treatments have been described in the art, including, for example, organometallic coupling agents and carboxylic acids, such as those described in U.S. Patent 8,647,510 (Davidson et al.). The encapsulated alkaline material may also optionally include a surface treatment.

[0126] Suitable copolymerizable organometallic compounds may have the general formula: CH2=C(CH3) m Si(OR) nOr CH2=C(CH3) m C = OOASi(OR) n Where m is 0 or 1, R is an alkyl group having 1 to 4 carbon atoms, A is a divalent organic linker, and n is 1 to 3. Organometallic coupling agents can be functionalized with reactive curing groups such as acrylates, methacrylates, vinyl groups, etc. Preferred coupling agents include γ-methacryloyloxypropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, etc.

[0127] In some embodiments, a combination of surface modifiers may be available, wherein at least one of these agents has a functional group that can copolymerize with the curable resin. Other surface modifiers that do not typically react with the curable resin may be included to improve dispersibility or rheological properties. Examples of this type of silane include, for example, aryl polyethers, alkyl, hydroxyalkyl, hydroxyaryl, or aminoalkyl-functionalized silanes.

[0128] Surface modification can be performed after mixing with the monomer or after mixing. It is generally preferred to combine the organosilane surface treatment compound with the nanoparticles before incorporation into the resin. The amount of surface modifier required depends on several factors, such as particle size, particle type, molecular weight of the modifier, and type of modifier. Generally, it is preferred to attach approximately a monolayer of modifier to the surface of the particles.

[0129] Various olefinically unsaturated monomers can be used in dental compositions. The olefinically unsaturated monomers in these dental compositions are typically stable liquids at about 25°C, meaning that the monomers generally do not polymerize, crystallize, or solidify when stored at room temperature (about 25°C) for a typical shelf life of at least 30, 60, or 90 days. The viscosity of the monomers typically changes (e.g., increases) by no more than 10% of the initial viscosity.

[0130] Especially for dental restorative compositions, olefinically unsaturated monomers generally have a refractive index of at least 1.50. In some embodiments, the refractive index is at least 1.51, 1.52, 1.53, or higher. The addition of sulfur atoms and / or the presence of one or more aromatic moieties can increase the refractive index (relative to monomers of the same molecular weight lacking such substituents).

[0131] Curable (e.g., dental) compositions may include a variety of other olefinically unsaturated compounds (with or without acidic functional groups), epoxy-functionalized (meth)acrylate resins, vinyl ethers, etc.

[0132] Dental compositions (e.g., photopolymerizable) may comprise a free radical polymerizable monomer, an oligomer, and a polymer having one or more olefinically unsaturated groups. Suitable compounds contain at least one olefinically unsaturated bond and are capable of undergoing addition polymerization. Examples of available olefinically unsaturated compounds include acrylates, methacrylates, hydroxyl-functionalized acrylates, hydroxyl-functionalized methacrylates, and combinations thereof.

[0133] These free-radical polymerizable compounds include mono-, di-, or poly(meth)acrylates (i.e., acrylates and methacrylates), such as methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-hexyl methacrylate, octadecyl methacrylate, allyl methacrylate, glycerol trimethacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, 1,3-propanediol dimethacrylate, trimethylolpropane trimethacrylate, 1,2,4-butanetriol trimethacrylate, 1,4-cyclohexanediol dimethacrylate, pentaerythritol tetramethacrylate, and sorbitol hexamethyl propylene. Acrylates, tetrahydrofurfuryl (meth)acrylate, bis[l-(2-acryloyloxy)]-p-ethoxyphenyl dimethylmethane, bis[l-(3-acryloyloxy-2-hydroxy)]-p-propoxyphenyl dimethylmethane, ethoxylated bisphenol A di(meth)acrylate and trihydroxyethyl isocyanurate tri(meth)acrylate; (meth)acrylamides (i.e., acrylamide and methacrylamide) such as (meth)acrylamide, methylene bis(meth)acrylamide and acetylacetone (meth)acrylamide; ureaalkyl (meth)acrylates; polyethylene glycol di(meth)acrylates (preferably with a molecular weight of 200-500); and vinyl compounds such as styrene, diallyl phthalate, divinyl succinate, divinyl adipate and divinyl phthalate. Other suitable free radical polymerizable compounds include siloxane-functionalized (meth)acrylates. Mixtures of two or more free radical polymerizable compounds may be used as needed.

[0134] Curable (e.g., dental) compositions may also contain monomers having hydroxyl and olefinically unsaturated groups in a single molecule. Examples of such materials include hydroxyalkyl (meth)acrylates, such as 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate; glyceryl mono(meth)acrylate or glyceryl di(meth)acrylate; trimethylolpropane mono(meth)acrylate or trimethylolpropane di(meth)acrylate; pentaerythritol mono(meth)acrylate, pentaerythritol di(meth)acrylate and pentaerythritol tri(meth)acrylate; sorbitol mono(meth)acrylate, sorbitol di(meth)acrylate, sorbitol tri(meth)acrylate, sorbitol tetra(meth)acrylate or sorbitol penta(meth)acrylate; and 2,2-bis[4-(2-hydroxy-3-ethylacryloyloxypropoxy)phenyl]propane (bisGMA). Suitable olefinic unsaturated compounds are available from a variety of commercial sources, such as Sigma-Aldrich, St. Louis.

[0135] In some embodiments, the first portion of the two-part curable (e.g., dental) composition comprises a monomer, such as HEMA, having a hydroxyl group and an olefinic unsaturated group in a single molecule. In some embodiments, the amount of the olefinic unsaturated compound having an acidic functional group (e.g., HEMA) is 5%, 10%, 15%, 20%, 25%, 30%, up to about 35%, 40%, 50%, or 45% by weight of the first portion of the two-part composition. Since the first portion represents only half of the total curable (e.g., dental) composition, the total concentration of the olefinic unsaturated compound having an acidic functional group (e.g., HEMA) is about half of the concentration just described.

[0136] The compositions described herein (e.g., dental) may comprise one or more curable components in the form of an olefinically unsaturated compound having an acidic functional group. Such components contain both an acidic group and an olefinically unsaturated group in a single molecule. When present, the polymerizable component optionally comprises an olefinically unsaturated compound having an acidic functional group. Preferably, the acidic functional group comprises an oxyacid of carbon, sulfur, phosphorus, or boron (i.e., an acid containing oxygen). However, in some embodiments, the dental composition is substantially free of (less than 1, 0.5, 0.25, 0.1, or 0.005%) an olefinically unsaturated compound having an acidic functional group.

[0137] As used herein, "acid-functionalized" olefinic unsaturated compounds include monomers, oligomers, and polymers having olefinic unsaturated groups as well as acid and / or acid precursor functional groups. Acid precursor functional groups include, for example, acid anhydrides, acyl halides, and pyrophosphates. Acidic functional groups may include carboxylic acid functional groups, phosphate functional groups, phosphonic acid functional groups, sulfonic acid functional groups, or combinations thereof.

[0138] Alkenyl unsaturated compounds with acidic functional groups include, for example, α,β-unsaturated acidic compounds such as glyceryl phosphate mono(meth)acrylate, glyceryl phosphate di(meth)acrylate (GDMA-P), hydroxyethyl methacrylate (e.g., HEMA) phosphate, bis((meth)acryloyloxyethyl) phosphate, ((meth)acryloyloxypropyl) phosphate, bis((meth)acryloyloxypropyl) phosphate, bis((meth)acryloyloxy)propoxy phosphate, (meth)acryloyloxyhexyl phosphate, bis((meth)acryloyloxyhexyl) phosphate, (meth)acryloyloxyoctyl Monomers, oligomers, and polymers of methyl phosphates, bis((meth)acryloyloxyoctyl)phosphates, (meth)acryloyloxydecyl)phosphates, bis((meth)acryloyloxydecyl)phosphates, caprolactone methacrylate, di- or tri-methacrylate of citrate, poly(meth)acrylated oligomaleic acid, poly(meth)acrylated polymaleic acid, poly(meth)acrylated poly(meth)acrylic acid, poly(meth)acrylated polycarboxy-polyphosphonic acid, poly(meth)acrylated polychlorophosphonic acid, poly(meth)acrylated polysulfonic acid, and poly(meth)acrylated polyboronic acid, etc., can be used as components. Unsaturated carbonic acids such as (meth)acrylic acid, aromatic (meth)acrylate acids (e.g., methacrylic acid-modified trimellitic acid), and their anhydrides can also be used.

[0139] Dental compositions may comprise olefinically unsaturated compounds having at least one P-OH moiety of acidic functional group. Such compositions are self-adhesive and anhydrous. For example, such compositions may comprise: a first compound comprising at least one (meth)acryloyloxy group and at least one -OP(O)(OH) group. x A group, wherein x = 1 or 2, and wherein at least one is -OP(O)(OH). x A group and at least one (meth)acryloyloxy group are linked together by a C1-C4 hydrocarbon group; a second compound comprising at least one (meth)acryloyloxy group and at least one -OP(O)(OH)x group, wherein x = 1 or 2, and wherein at least one -OP(O)(OH)x group and at least one (meth)acryloyloxy group are linked together by a C5-C12 hydrocarbon group; an olefinic unsaturated compound without acidic functional groups; an initiator system; and a filler.

[0140] Initiators are typically added to mixtures of polymerizable components. Initiators are sufficiently miscible with the resin system to facilitate their dissolution in the polymerizable composition (and prevent separation from the polymerizable composition). Typically, the initiator is present in the composition in an effective amount, such as from about 0.1% by weight to about 5.0% by weight, based on the total weight of the composition.

[0141] In some embodiments, the mixture of monomers is photopolymerizable and the composition contains a photoinitiator (i.e., a photoinitiator system) that initiates polymerization (or hardening) of the composition upon irradiation with photochemical radiation. Such photopolymerizable compositions may be free-radical polymerizable. Photoinitiators typically have a functional wavelength in the range of about 250 nm to about 800 nm. Suitable photoinitiators (i.e., photoinitiator systems comprising one or more compounds) for polymerizing free-radical photopolymerizable compositions include binary and ternary systems. Typical ternary photoinitiators comprise an iodonium salt, a photosensitizer, and an electron donor compound, as described in U.S. Patent 5,545,676 (Palazzotto et al.). Iodonium salts include diaryliodonium salts, such as diphenyliodonium chloride, diphenyliodonium hexafluorophosphate, and diphenyliodonium tetrafluoroborate. Some preferred photosensitizers may include monoketones and diketones (e.g., α-diketones) that absorb light in the range of about 300 nm to about 800 nm (preferably about 400 nm to about 500 nm), such as camphorquinone, biphenylyl, bifuranyl, 3,3,6,6-tetramethylcyclohexanedione, phenanthrenequinone, and other cyclic α-diketones. Camphorquinone is generally preferred. Preferred electron donor compounds include substituted amines, for example, ethyl 4-(N,N-dimethylamino)benzoate.

[0142] Other photoinitiators suitable for polymerizing compositions capable of free radical photopolymerization include phosphine oxides, which typically have a functional wavelength in the range of about 380 nm to about 1200 nm. Preferred phosphine oxide radical initiators with functional wavelengths in the range of about 380 nm to about 450 nm are acylphosphine oxides and diacylphosphine oxides.

[0143] Commercially available phosphine oxide photoinitiators capable of free radical initiation when irradiated at wavelengths greater than about 380 nm to about 450 nm include bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (IRGACURE 819, Ciba Specialty Chemicals, Tarrytown, NY), bis(2,6-dimethoxybenzoyl)-(2,4,4-trimethylpentyl)phosphine oxide (CGI 403, Ciba Specialty Chemicals), and a 25:75 weight mixture of bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide and 2-hydroxy-2-methyl-1-phenylprop-1-one (IRGACURE). 1700, Ciba Specialty Chemicals, Inc.), a 1:1 mixture by weight of bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide and 2-hydroxy-2-methyl-1-phenyl-1-propanone (DAROCUR 4265, Ciba Specialty Chemicals, Inc.) and ethyl 2,4,6-trimethylbenzylphenylphosphine (LUCIRIN LR8893X, BASF Corp., Charlotte, NC, North Carolina).

[0144] Tertiary amines can be used in combination with acylphosphine oxides. Exemplary tertiary amines include ethyl 4-(N,N-dimethylamino)benzoate and N,N-dimethylaminoethyl methacrylate. The amine reducing agent, when present, is present in the photopolymerizable composition in an amount of about 0.1% to about 5.0% by weight, based on the total weight of the composition. In some embodiments, the curable dental composition can be irradiated with ultraviolet (UV) light or blue light. For this implementation, suitable photoinitiators include those available under the trade names IRGACURE and DAROCUR from Ciba Speciality Chemical Corp., Tarrytown, NY, and include 1-hydroxycyclohexylphenyl ketone (IRGACURE 184), 2,2-dimethoxy-1,2-diphenylethyl-1-one (IRGACURE 651), bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (IRGACURE 819), 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propane-1-one (IRGACURE 2959), 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone (IRGACURE 369), and 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropane-1-one (IRGACURE 369). 907) and 2-hydroxy-2-methyl-1-phenylprop-1-one (DAROCUR 1173).

[0145] Photopolymerizable compositions are typically prepared by mixing various components of the composition. In embodiments where the photopolymerizable composition cures in the absence of air, the photoinitiators are combined under “safe light” conditions (i.e., conditions that do not cause premature curing of the composition). If desired, a suitable inert solvent may be used when preparing the mixture. Examples of suitable solvents include acetone and dichloromethane.

[0146] Hardening is achieved by contacting the composition with a radiation source, preferably a visible light source. Light sources emitting photochemical radiation between 250 nm and 800 nm (especially blue light with wavelengths of 380-520 nm) can be readily employed, such as quartz halogen lamps, tungsten-halogen lamps, mercury arcs, carbon arcs, low-, medium-, and high-pressure mercury lamps, plasma arcs, light-emitting diodes, and lasers. Typically, the available light source has a range of 0.200-6000 mW / cm². 2 Strength within the specified range. 1000 mW / cm 2 The strength of the light source typically provides the required curing. Various conventional light sources can be used to harden such compositions.

[0147] Optionally, the composition may comprise a solvent (e.g., an alcohol (e.g., propanol, ethanol), a ketone (e.g., acetone, methyl ethyl ketone), an ester (e.g., ethyl acetate), other non-aqueous solvents (e.g., dimethylformamide, dimethylacetamide, dimethyl sulfoxide, 1-methyl-2-pyrrolidone)) and water. In some embodiments, (e.g., a portion) of the dental composition comprises water, typically not exceeding 5% by weight of the total dental composition.

[0148] If desired, the composition may contain additives such as indicators, dyes (including photobleachable dyes), pigments, inhibitors, accelerators, viscosity modifiers, wetting agents, buffers, free radical and cationic stabilizers (e.g., BHT), and other similar components that are obvious to those skilled in the art.

[0149] Additionally, pharmaceutical agents or other therapeutic substances may optionally be added to the dental composition. Examples include, but are not limited to, fluoride sources, whitening agents, caries inhibitors (e.g., xylitol), calcium sources, phosphorus sources, remineralizing agents (e.g., calcium phosphate compounds), enzymes, breath fresheners, anesthetics, coagulants, acid neutralizers, chemotherapeutic agents, immunomodulators, thixotropic gums, polyols, anti-inflammatory agents, antimicrobial agents (other than antimicrobial lipid components), antifungal agents, agents for treating dry mouth, desensitizing agents, and other types commonly used in dental compositions. Combinations of any of the above additives may also be used. The selection and amount of any such additive can be chosen by those skilled in the art to obtain the desired results without excessive experimentation.

[0150] As is known in the art, curable dental compositions can be used to treat oral surfaces, such as teeth. In some embodiments, the composition can be hardened by curing after application of the dental composition. For example, when a curable dental composition is used as a restorative agent such as a tooth filling, the method typically involves applying the curable composition to an oral surface (e.g., a carious tooth) and curing the composition. In some embodiments, a dental adhesive can be applied prior to the application of the curable dental restorative material described herein. Dental adhesives are also typically hardened by curing simultaneously with the curing of a highly filled dental restorative composition. Methods of treating oral surfaces may include providing a dental article and adhering the dental article to an oral surface (e.g., a tooth).

[0151] In one embodiment, the cured dental composition can be used for pulp capping. In this embodiment, cell proliferation of dental pulp stem cells in contact with the cured dental composition (e.g., the same molded disc used for the buffer disc test) is evaluated in a manner further described in detail in the examples. The average cell proliferation is at least 75% of the control (where the disc does not contain the cured dental composition). In some embodiments, the average cell proliferation is at least 80%, 85%, or 90% of the control. The average alkaline phosphatase (ALP) activity is also increased compared to the control. In some embodiments, the average ALP activity is at least 0.4 mU / mL, 0.5 mU / mL, 0.6 mU / mL, 0.7 mU / mL, 0.8 mU / mL, 0.9 mU / mL, 1.0 mU / mL, and at most 1.1 mU / mL or 1.2 mU / mL or greater.

[0152] In another embodiment, the cured dental composition can be used as an adhesive. The cured dental composition can exhibit an adhesive strength of at least 1 MPa, 2 MPa, 3 MPa, 4 MPa, 5 MPa, 6 MPa, 8 MPa, 9 MPa, or 10 MPa, as measured by the test methods described in the examples. In some embodiments, the adhesive strength can be up to 20 MPa or greater.

[0153] As used herein, “dental composition” refers to a material containing fillers capable of adhering to or bonding to oral surfaces. Curable dental compositions can be used to bond dental articles to tooth structures, form coatings (e.g., sealants or varnishes) on tooth surfaces, serve as restorative agents placed directly in the mouth and cured in situ, or alternatively for the manufacture of prostheses outside the mouth, which are then adhered to inside the mouth.

[0154] Curable dental compositions include, for example, adhesives (e.g., dental and / orthodontic adhesives), cements (e.g., two-part cements), primers (e.g., orthodontic primers), linings (applied to the base of carious teeth to reduce tooth sensitivity), root canals and pulp caps, coatings such as sealants (e.g., fissures) and varnishes; and resin restorative agents (also known as direct composites), such as dental fillers, and crowns, bridges, and articles for dental implants. Highly filled dental compositions are also used in blanks from which crowns can be ground. Composites are highly filled pastes designed to fill large defects in the tooth structure. Dental cements, compared to composites, are materials with less filling and lower viscosity, and often act as a binder for additional materials such as inlays, onlays, etc., or act as a filling material themselves when applied to multiple layers and cured. Dental cements are also used to permanently bond dental restorative articles such as crowns, bridges, or orthodontic appliances to tooth surfaces or implant supports.

[0155] As used herein, “dental articles” refers to articles that can be adhered to (e.g., bonded) to tooth structures or dental implants. Dental articles include, for example, crowns, bridges, veneers, inlays, onlays, fillings, orthodontic appliances and devices.

[0156] "Orthodontic appliance" means any device designed to be bonded to the dental structure, including but not limited to orthodontic brackets, buccal tubes, lingual retainers, orthodontic braces, bite openers, snaps, and wedges. The appliance has a base for receiving the adhesive, and this base can be a flange made of metal, plastic, ceramic, or combinations thereof. Alternatively, the base can be a custom base formed of one or more cured adhesive layers (i.e., a single or multiple layer of adhesive).

[0157] "Oral surface" refers to the soft or hard surfaces in the oral cavity. Hard surfaces typically include tooth structures, such as natural and artificial tooth surfaces, bone, and so on.

[0158] "Cureable" and "curable" describe materials or compositions that can be cured (e.g., polymerized or crosslinked) by means of heat initiating polymerization and / or crosslinking; photochemical irradiation initiating polymerization and / or crosslinking; and / or mixing one or more components to initiate polymerization and / or crosslinking. "Mixing" can be achieved, for example, by combining two or more components and mixing them to form a homogeneous composition. Alternatively, the two or more components can be provided as separate layers that mix with each other at the interface (e.g., spontaneously or upon application of shear stress) to initiate polymerization.

[0159] "Cured" refers to materials or compositions that have been cured (e.g., polymerized or cross-linked).

[0160] "Curing agent" refers to a substance that causes resin to harden. Curing agents may include, for example, polymerization initiator systems, photoinitiator systems, thermal initiators, and / or redox initiator systems.

[0161] "(Meth)acrylate" is an abbreviation for acrylate, methacrylate or combinations thereof; "(Meth)acrylic acid" is an abbreviation for acrylic acid, methacrylic acid or combinations thereof; and "(Methacryl)acryloyl" is an abbreviation for acryloyl, methacryloyl or combinations thereof.

[0162] As used herein, “a,” “an,” “the,” “at least one,” and “one or more” are used interchangeably.

[0163] In addition, in this paper, the numerical range expressed by the endpoints includes all the numerical values ​​contained in that range (for example, 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc.).

[0164] Example :

[0165] Material

[0166] Hydroxyethyl methacrylate (HEMA) was obtained from Evonik Industries, Sarasota, FL.

[0167] Ethyl ethyl-4-dimethylaminobenzoate (EDMAB) is derived from Sigma Aldrich Corporation, Louis, MO, Missouri.

[0168] Camphorquinone (CPQ) was obtained from Sigma-Aldrich.

[0169] 2,6-Di-tert-butyl-4-methylphenol (BHT) was obtained from PMC Specialties Incorporated, Cincinnati, OH.

[0170] The pyrolytic silica R812S was obtained from Degussa-Huls Corporation, Parsippany, NJ.

[0171] Calcium glycerophosphate was obtained from Spectrum Laboratory Products, Gardena, CA.

[0172] Yttrium fluoride (YbF3) was obtained from Treibacher Industrial Incorporated, Toronto, Canada.

[0173] The buffer solution BDH5018 (aqueous potassium hydrogen phthalate buffer solution adjusted to pH 4.00 with hydrochloric acid at 25°C) was obtained from VWR International, Radnor, PA.

[0174] VBP polymer was prepared by reacting a PAA:ITA copolymer with a sufficient amount of IEM (2-isocyanate ethyl methacrylate) to convert 16 mol% of the copolymer's acid radicals into side-chain methacrylate groups, according to Example 11 of U.S. Patent 5,130,347 (Mitra).

[0175] The PAA:ITA copolymer was prepared from acrylic acid:itacic acid in a 4:1 molar ratio according to Example 3 of U.S. Patent 5,130,347.

[0176] The Zr / Si nanocluster filler was prepared essentially as described in U.S. Patent 6,730,156 [Preparation Example A (lines 51-64) and Example B (column 25, line 65 to line 26, line 40)].

[0177] Portland Cement: White Portland Cement (Federal White Type 1, ASTM C150) was purchased from Woodstock, Ontario, Canada. The major components of the composition, as reported by the manufacturer, are tricalcium silicate (3CaO-SiO2), dicalcium silicate (2CaO-SiO2), tricalcium aluminate (3CaO-Al2O3), tetracalcium aluminoferrite (4CaO-Al2O3-Fe2O3), magnesium oxide, calcium oxide, potassium sulfate, and sodium sulfate. Portland Cement is a strongly alkaline material containing multiple components. Each major component (excluding trace amounts of magnesium oxide, potassium sulfate, and sodium sulfate) contains a significant amount of the strong base (CaO). Portland Cement typically contains approximately 61%–69% CaO, approximately 18%–24% SiO2, approximately 2%–6% Al2O3, approximately 1%–6% Fe2O3, and approximately 0.5%–5% MgO.

[0178] Bioactive glass [45S5] is prepared using the following composition: SiO2 (45 wt%), Na2O (24.5 wt%), CaO (24.5 wt%), and P2O5 (6 wt%). The bioactive glass is a strongly alkaline material. It is homogeneous and contains 49 wt% of two strongly alkaline components (Na2O and CaO) in the total composition.

[0179] Tricalcium silicate (3CaO-SiO2) powder was prepared via a sol-gel method. A solution was prepared by continuously stirring with 0.5 mol of Si(OC2H5)4 (tetramethyl orthosilicate, TEOS), 200 ml of water, and nitric acid as a catalyst. Then, 1.5 mol of Ca(NO3)2-4H2O was added to the solution. The solution was heated to 60°C and held until gelation occurred. The solid was then dried at 200°C and calcined at 1500°C for 6 hours. Tricalcium silicate is a strongly basic homogeneous compound with approximately 74 wt% of a strong base component (CaO).

[0180] Fluoroaluminosilicate (FAS) glass was prepared essentially as described in Example 1 of U.S. Patent 5,154,762. A powder composition consisting of mixed SiO2 (34.6 wt%), AlF3 (21.5 wt%), SrO (18.7 wt%), Al2O3 (9.4 wt%), AlPO4 (6.5 wt%), Na2AlF6 (5.6 wt%), and P2O5 (3.7 wt%) was melted in an electric arc furnace at 1350–1450 °C and rolled to form an amorphous single-phase FAS glass. The glass was then ball-milled to provide a glass with a diameter of 2.6 μm. 2 / g surface area of ​​the pulverized product (measured according to the Brunauer, Emmet and Teller (BET) method).

[0181] calculate

[0182] The following formulas 1-6 are used to calculate the shell thickness, core material weight % and shell material weight % of the encapsulated material prepared by the methods described in Examples 1-5. In the calculations, the core material powder particles are represented as spheres (surface area = 4π(d / 2)). 2 Volume = (4 / 3)(π)(d / 2) 3 To determine the total surface area of ​​the core material.

[0183] Formula 1:

[0184] ST em = V mo

[0185] SA c

[0186] ST em(cm) = The thickness of the encapsulating material.

[0187] V mo (cm 3 = Volume of the metal oxide prepared by the APCVD method.

[0188] SA c (cm 2 = Total surface area of ​​the core material powder.

[0189] Formula 2:

[0190]

[0191] FR cg (cm 3 / min) = Carrier gas flow rate (for Al2Me6, TiCl4, SiCl4).

[0192] CT(min) = coating time.

[0193] CA = cation per mole of precursor material.

[0194] MW mo (g / mol) = molecular weight per mole of cationic metal oxide (for Al2O3MW) mo =51 g / mol, for TiO2MW mo =80 g / mol, for SiO2MW mo =60g / mol).

[0195] D mo (g / cm 3 ) = Density of metal oxides (for Al2O3D) mo =3.0, for TiO2D mo =3.0, for SiO2D mo =2.2).

[0196] %P = the molar percentage of the metal oxide precursor contained in the carrier gas (%P = 1.33% for Al2Me6, %P = 1.33% for TiCl4, and %P = 35.7% for SiCl4).

[0197] EDE = Estimated deposition efficiency of APCVD used in the examples (EDE = 0.5 for Al2O3, EDE = 0.6 for TiO2, EDE = 0.4 for SiO2).

[0198] Formula 3:

[0199]

[0200] Ncp = The number of powder particles in the core material.

[0201] Formula 4:

[0202]

[0203] Mcp(g) = The amount of core powder material (bioactive glass, Portland binder, tricalcium silicate) used in the APCVD method.

[0204] Msm(g) = The amount of metal oxides (Al2O3, TiO2, SiO2) deposited by APCVD.

[0205] Msm(g)=V mo *D mo

[0206] D cp (g / cm 3 = Density of the core powder material (Dcp = 2.65 for bioactive glass, Dcp = 3.11 for Portland adhesive).

[0207] d(cm) = diameter of the core particle.

[0208] Formulas 5 and 6 - Weight percentage (wt%) of the encapsulating material:

[0209]

[0210] Core weight percentage = (100 - shell weight percentage).

[0211] For materials encapsulated with a tricalcium silicate core, the core particles have additional porosity that affects the apparent surface area determination. For tricalcium silicate-encapsulated materials, an indirect method is used to estimate the effective surface area of ​​the core and the thickness of the shell coating. It is estimated that tricalcium silicate-encapsulated materials and Portland adhesive-encapsulated materials (with the same shell material) have the same shell thickness, requiring approximately the same time to change the pH of the buffer solution from 4 to 9 (according to the process in Examples 6-9). Therefore, the shell thickness of the tricalcium silicate-encapsulated material is calculated based on the corresponding value for the Portland adhesive-encapsulated material.

[0212] Example 1: Encapsulation material with bioactive glass core

[0213] Bioactive glass (BG) powder was encapsulated with an alumina (AO)-based material using atmospheric pressure chemical vapor deposition (APCVD). The bioactive glass was coated by reacting trimethylaluminum (obtained from Strem Chemicals, Newburyport, MA, and dispensed using a stainless steel bubbler) with water vapor in a fluidized bed reactor. The reactor was a glass frit funnel tube (2 cm diameter, 18 cm height). The reactor had an inlet pipe extending below the glass frit path parallel to the reactor body and an extended top region above the glass frit to allow for desired reactor height and fittings for the precursor injector pipe and vent. The temperature was controlled at 180°C using an oil bath. A nitrogen carrier gas with a standard bubbler configuration for liquid precursors was used. The bubbler was maintained at an ambient temperature of approximately 22°C. The flow rate through the trimethylaluminum (TMA) bubbler was 100–330 cm⁻¹. 3 The flow rate through the water bubbler is in the range of 250-1250 cm / min. 3 The coating time was within the range of 20-100 minutes. Encapsulated material AJ was prepared by varying the following parameters: the amount of bioactive glass added, the particle size of the bioactive glass powder, the TMA flow rate, the water flow rate, and the coating time. Table 1 lists the encapsulation parameters for encapsulated material AJ. For encapsulated material GJ, a larger reactor (4 cm diameter, 30 cm height) was used. For encapsulated materials AC and GJ, the particle size of the bioactive glass powder was selected before addition to the reactor by passing the powder through a 45-micron sieve and collecting it on a 38-micron sieve. For encapsulated material DF, the bioactive glass powder was milled using a ball mill with 5 mm media to obtain a 10-micron particle size before addition to the reactor. The average particle size of each powder after milling was determined using a LA950 laser particle size analyzer (Horiba Scientific, Edison, NJ) with water.

[0214] Table 1a reports the calculated values ​​of shell thickness (nanometers), core weight % and shell weight % for each encapsulation material AJ.

[0215] Table 1: Bioactive Glass Encapsulated Using APCVD

[0216]

[0217] Table 1a: Encapsulated Bioactive Glass Materials

[0218] Encapsulation material Shell thickness (nm) Core weight % % of shell weight A 37 99.5 0.5 B 94 98.5 1.5 C 187 97 3 D 33 98 2 E 104 94 6 F 149 91 9 G 124 98 2 H 93 98.5 1.5 I 62 99 1 J 124 98 2

[0219] Example 2: Materials encapsulated with tricalcium silicate

[0220] Tricalcium silicate (TCS) was encapsulated with an alumina-based material using atmospheric pressure chemical vapor deposition (APCVD). The tricalcium silicate powder (30 g) was coated by reacting trimethylaluminum (obtained from Strem Chemicals and dispensed using a stainless steel bubbler) with water vapor in a fluidized bed reactor. The reactor was a glass frit funnel tube (4 cm diameter, 30 cm height). The reactor had an inlet pipe extending below the glass frit path parallel to the reactor body and an extended top region above the glass frit to allow for the desired reactor height and fittings for the precursor injector pipe and vent. The temperature was controlled at 180°C using an oil bath. A nitrogen carrier gas with a standard bubbler configuration for liquid precursors was used. The bubbler was maintained at an ambient temperature of approximately 22°C. The flow rate through the trimethylaluminum (TMA) bubbler was 500 cm⁻¹. 3 / minute. The flow rate through the water bubbler is 1750 cm⁻¹. 3 / min. The total coating time was 40 minutes. Table 2 lists the average particle size and other encapsulation parameters of the tricalcium silicate powder added to the reactor. After the coating process, the resulting encapsulated material was individually sieved to collect encapsulated material with a particle size of less than 38 micrometers. These sieved encapsulated materials were designated as encapsulated materials K and L.

[0221] Table 2a reports the calculated values ​​of shell thickness (nanometers), core weight % and shell weight % for each encapsulation material KL.

[0222] Table 2: Tricalcium silicate encapsulated using APCVD method

[0223]

[0224] Table 2a: Encapsulated tricalcium silicate materials

[0225] Encapsulation material Shell thickness (nm) Core weight % % of shell weight K 35 99 1 L 32 99 1

[0226] Example 3: Encapsulated material with Portland adhesive core

[0227] Portland binder (PC) was encapsulated with an alumina-based material using atmospheric pressure chemical vapor deposition (APCVD). The Portland binder powder was coated by reacting trimethylaluminum (obtained from Strem Chemicals and dispensed using a stainless steel bubbler) with water vapor in a fluidized bed reactor. The reactor was a glass frit funnel tube (4 cm diameter, 30 cm height). The reactor had an inlet pipe extending below the glass frit path parallel to the reactor body and an extended top region above the glass frit to allow for the desired reactor height and fittings for the precursor injector pipe and vent. The temperature was controlled at 180°C using an oil bath. A nitrogen carrier gas with a standard bubbler configuration for liquid precursors was used. The bubbler was maintained at an ambient temperature of approximately 22°C. The flow rate through the trimethylaluminum (TMA) bubbler was 240–1000 cm⁻¹. 3 The flow rate through the water bubbler is in the range of 610-2500 cm / min. 3 The coating time is within the range of ( / minute). The total coating time is within the range of 10-105 minutes. The encapsulated material MU is prepared by changing the following parameters: the amount of Portland binder added, the particle size of the Portland binder powder, the TMA flow rate, the water flow rate, and the coating time. Table 3 lists the encapsulation parameters of the encapsulated material MU.

[0228] For the encapsulated material M, the Portland binder powder added to the reactor is used directly in the received state and has a size of 17.1 microns (D10-D90 range of 6.0-33.5) as determined using a Coulter multisizer 3 (Beckman Coulter Company, CA).

[0229] For the encapsulated material NS, fine particles were removed from the Portland binder sample by air classification using an AVEKA CCE Model 100 centrifugal air classifier (AVEKA CCE LLC, Cottage Grove, MN) before being added to the reactor. Parameters were selected to obtain a 56% crude material yield, providing a sample with an average particle size of 24.4 micrometers (D10-D90 range of 13.8-38.4 micrometers) as determined using a Coulter Multisizer 3 counter (Beckman Coulter Company).

[0230] For the encapsulated material TU, fine and coarse particles were removed from the Portland binder sample using an AVEKA CCE centrifugal air classifier 100 before being added to the reactor. In the first step, approximately 24% of the coarse tailings from the initial sample were removed, and then in the second step, approximately 25% of the fine tailings were removed from the remaining sample. The resulting Portland binder powder had an average particle size of 19.6 micrometers (D10-D90 range of 9.4-31.5 micrometers) as determined using a Coulter multisizer 3 (Beckman Coulter Company).

[0231] Table 3a reports the calculated values ​​of shell thickness (nanometers), core weight % and shell weight % for each encapsulation material MU.

[0232] Table 3: Portland adhesives encapsulated using the APCVD method

[0233]

[0234] Table 3a: Encapsulated Portland adhesive materials

[0235] Encapsulation material Shell thickness (nm) Core weight % % of shell weight M 161 95 5 N 204 95.5 4.5 O 109 97.5 2.5 P 57 98.5 1.5 Q 26 99.5 0.5 R 13 99.7 0.3 S 51 99 1 T 51 98.5 1.5 U 69 98 2

[0236] Example 4: Encapsulation material with Portland adhesive core and titanium dioxide shell

[0237] Portland binder was encapsulated with a titanium dioxide-based material using atmospheric pressure chemical vapor deposition (APCVD). The Portland binder powder (50 g) was coated by reacting titanium tetrachloride (obtained from Strem Chemicals and dispensed using a stainless steel bubbler) with water vapor in a fluidized bed reactor. Fine particles were removed from the Portland binder sample using the air sorting process described for the encapsulation material NS in Example 3 prior to feeding into the reactor. The resulting powder had an average particle size of 24.4 micrometers (D10-D90 range of 13.8-38.4 micrometers) as determined using a Coulter multisizer 3 (Beckman Coulter Company). The reactor was a glass frit funnel tube (4 cm diameter, 30 cm height). The reactor had an inlet pipe extending below the glass frit path parallel to the reactor body and an extended top region above the glass frit to allow for the desired reactor height and fittings for the precursor injector pipe and vent. The temperature was controlled at 180°C using an oil bath. A nitrogen carrier gas is used, equipped with a standard bubbler configuration for liquid precursors. The bubbler is maintained at an ambient temperature of approximately 22°C. The flow rate through the titanium tetrachloride bubbler is 1000 cm⁻¹. 3 / minute. The flow rate through the water bubbler is 1000 cm / min. 3 / minute. Total coating time is 57 minutes.

[0238] Example 5: Encapsulation material with Portland adhesive core and silica shell

[0239] Portland binder was encapsulated with a silica-based material using atmospheric pressure chemical vapor deposition (APCVD). The Portland binder powder (50 g) was coated by reacting silicon tetrachloride (obtained from Strem Chemicals and dispensed using a stainless steel bubbler) with water vapor in a fluidized bed reactor. Fine particles were removed from the Portland binder sample using an air sorting process described for the encapsulation material NS in Example 3 prior to feeding into the reactor. The resulting powder had an average particle size of 24.4 micrometers (D10-D90 range of 13.8-38.4 micrometers) as determined using a Coulter multisizer 3 (Beckman Coulter Company). The reactor was a glass frit funnel tube (4 cm diameter, 30 cm height). The reactor had an inlet pipe extending below the glass frit path parallel to the reactor body and an extended top region above the glass frit to allow for the desired reactor height and fittings for the precursor injector pipe and vent. The temperature was controlled at 180°C using an oil bath. Use nitrogen carrier gas with a standard bubbler configuration for liquid precursors. Maintain the bubbler at an ambient temperature of approximately 22°C. The flow rate through the silicon tetrachloride bubbler is 60 cm⁻¹. 3 / minute. The flow rate through the water bubbler is 1300 cm / min. 3 / minute. Total coating time is 58 minutes.

[0240] Table 3b reports the calculated values ​​of the shell thickness (nanometers), core weight % and shell weight % of the encapsulated materials for Examples 4 and 5.

[0241] Table 3b: Encapsulated Portland Adhesive Materials

[0242] Encapsulation material Shell thickness (nm) Core weight % % of shell weight Example 4 137 97.0 3.0 Example 5 154 97.5 2.5

[0243] Example 6 :

[0244] Each of the four glass vials was filled with 15g of deionized water and 10g of pH 4 buffer solution (Buffer Solution BDH5018, VWR International), and the solutions were stirred. Unencapsulated Portland adhesive (0.25g, 24.4μm particle size) was added to the first vial. Unencapsulated FAS glass (0.25g) was added to the first vial. Encapsulated material O (0.25g) was added to the first vial. Encapsulated material Q (0.25g) was added to the first vial. Stirring was continued in the vials, and the pH of each solution was measured over 8 to 10 minutes using a Mettler Toledo M300 pH meter (Mettler Toledo Corporation, Columbus, Ohio). A thicker shell was produced by varying the coating time with longer coating times to modify the shell thickness of the encapsulated material. The shell of encapsulated material O was approximately 4.25 times thicker than the shell of encapsulated material Q. The results are shown in Table 4, which demonstrates that the encapsulated material provides a delayed reaction with the alkaline core material or a delayed release of the alkaline core material.

[0245] Table 4: pH Measurements of Portland Adhesive Encapsulated with Varying Shell Thickness

[0246]

[0247] Example 7 :

[0248] Two glass vials were each filled with 15 g of deionized water and 10 g of pH 4 buffer solution (buffer solution BDH5018, VWR International) and the solutions were stirred. 0.25 g of the titanium dioxide-encapsulated material from Example 4 was added to each vial. 0.25 g of the silica-encapsulated material from Example 5 was added to each vial. Stirring was continued in the vials, and the pH of each solution was measured over 45 minutes using a Mettler Toledo M300 pH meter (Mettler Toledo Corporation). The results are shown in Table 5, and the results indicate that the encapsulated material provides a delayed reaction with or a delayed release of the alkaline core material.

[0249] Table 5: pH Measurement of Portland Adhesive Encapsulated in Titanium Dioxide and Silica Shells

[0250]

[0251] Example 8 :

[0252] Three glass vials were each filled with 15g of deionized water and 10g of pH 4 buffer solution (Buffer Solution BDH5018, VWR International) and the solutions were stirred. Unencapsulated tricalcium silicate (0.25g) was added to the first vial. Encapsulated material K (0.25g) was added to the second vial. Encapsulated material L (0.25g) was added to the third vial. Stirring was continued in the vials, and the pH of each solution was measured over 12 minutes using a Mettler Toledo M300 pH meter (Mettler-Toledo Corporation). The results are shown in Table 6, and the results indicate that the encapsulated material provides a delayed reaction with or a delayed release of the alkaline core material.

[0253] Table 6: pH Measurement of Tricalcium Silicate Encapsulated in Alumina Shells

[0254]

[0255] Example 9 :

[0256] Four glass vials were each filled with 15g of deionized water and 10g of pH 4 buffer solution (Buffer Solution BDH5018, VWR International) and the solutions were stirred. Encapsulating material O (0.25g) was added to the first vial. Encapsulating material P (0.25g) was added to the second vial. Encapsulating material Q (0.25g) was added to the third vial. Encapsulating material R (0.25g) was added to the fourth vial. Stirring continued in the vials, and the pH of each solution was measured using a Mettler Toledo M300 pH meter (Mettler Toledo Corporation). The time it took for each solution to reach pH 9 was recorded. The results are shown in Table 7, and the results indicate that the delayed release of the alkaline core material depends on the thickness of the shell. A thicker shell was produced by modifying the shell thickness of the encapsulating material by varying the coating time with a longer coating time. The thickness of the alumina shell of the encapsulating material OR gradually decreases as follows: Shell thickness: Encapsulating material O > Encapsulating material P > Encapsulating material Q > Encapsulating material O > Encapsulating material R. The relative shell thickness of the encapsulating materials OR is approximately 8.5:4.5:2:1 (Table 7).

[0257] Table 7: pH Measurement of Portland Adhesive Encapsulated in Alumina Shell

[0258]

[0259] Example 10 :

[0260] Two glass vials were each filled with 15 g of deionized water and 10 g of pH 4 buffer solution (Buffer Solution BDH5018, VWR International) and the solutions were stirred. Unencapsulated bioactive glass (0.25 g, 38-45 μm particle size) was added to the first vial. Encapsulated material J (0.25 g) was added to the second vial. Stirring continued in the vials, and the pH of each solution was measured over 60 minutes using a Mettler Toledo M300 pH meter (Mettler Toledo Corporation). The results are shown in Table 8, and the results indicate that the encapsulated material provides a delayed reaction with or a delayed release of the alkaline core material.

[0261] Table 8: pH Measurements of Bioactive Glass Encapsulated in Alumina Shells

[0262]

[0263] Example 11 :

[0264] Two glass vials were each filled with 25 g of deionized water. Unencapsulated Portland binder (0.25 g, 24.4 μm particle size) was added to the first vial. Encapsulated material P (0.25 g) was added to the second vial. The contents were stirred, and the pH of each solution was measured over 5 minutes using a Mettler Toledo M300 pH meter (Mettler Toledo Corporation). The results are shown in Table 9, and the results indicate that the encapsulated material provides a delayed reaction or release of the alkaline core material.

[0265] Table 9: pH Measurement of Portland Adhesive Encapsulated in Alumina Shell

[0266]

[0267] Example 12 :

[0268] Two glass vials were each filled with 25 g of deionized water. Unencapsulated bioactive glass (0.25 g, 38.45 μm particle size) was added to the first vial. Encapsulated material J (0.25 g) was added to the second vial. The contents were stirred, and the pH of each solution was measured over 3 minutes using a Mettler Toledo M300 pH meter (Mettler Toledo Corporation). The results are shown in Table 10, and the results indicate that the encapsulated material provides a delayed reaction with or a delayed release of the alkaline core material.

[0269] Table 10: pH Measurement of Bioactive Glass Encapsulated in Alumina Shells

[0270]

[0271] Example 13 (Comparative) :

[0272] Add 25g of deionized water to a glass vial and add 0.25g of unsealed FAS glass to the vial. Stir the contents and measure the pH of the solution over 3 minutes using a Mettler Toledo M300 pH meter (Mettler-Toledo Corporation). The results are shown in Table 11.

[0273] Table 11: pH Measurement of Unencapsulated FAS Glass

[0274]

[0275] Example 14: Dental composition of a material with bioactive glass encapsulation

[0276] Dental compositions 1-6 (DC-1 to DC-6) are prepared using a paste selected from pastes B1-B6 as the first part of the composition and paste A as the second part of the composition.

[0277] The composition of paste A is reported in Table 12 (each component is reported as % by weight). Paste A was prepared in batches. BHT and CPQ were added to a mixing cup containing HEMA. The filled cup was placed in a FlackTek SPEEDMIXER (FlackTek Incorporated, Landrum, SC, South Carolina) and the contents were mixed at 2500 rpm until a homogeneous mixture was obtained. Then the mixture of VBP in water was added to the cup and mixing was continued. CGP, Zr / Si nanoclusters, and yttrium fluoride components were combined to form a homogeneous mixture and then added to the cup. Mixing was continued until homogeneous. The resulting paste was stored at 4°C when not in use.

[0278] The compositions of pastes B1-B4 and paste BA are reported in Table 13 (each component is reported as % by weight). Pastes B1-B4 and paste BA were prepared by adding EDMAB to a flask containing HEMA and mixing. In separate beakers, FAS glass, encapsulating material H (from Table 1), and pyrolytic silica were mixed to form a homogeneous mixture. The EDMAB / HEMA mixture was then added to the mixture in the beakers, and the contents were stirred until homogeneous. The beakers were covered, and the pastes were used within 24 hours of preparation.

[0279] The compositions of pastes B5 and B6 are reported in Table 14, and the pastes are prepared according to the general methods described above for pastes B1-B4.

[0280] For dental composition 1, paste B1 is the first part of the composition. Combine paste A and paste 1 (by weight 1:1) of DC-1 on a mixing pad and scrape until homogeneous (mixing for approximately 10–30 seconds). Immediately measure the pH of the resulting paste using an ORION PERPHECTROSS pH microelectrode (catalog number 8220BNWP, Thermo Fisher Scientific Company, Waltham, PA). Record the pH reading 30 seconds after inserting the probe into the paste. The recorded pH is 4.3. Immediately fill a Teflon disc mold (3.1 mm diameter and 1.3 mm height) with the paste and then cure for 20 seconds on each side of the mold using an ELIPAR S10 curing light (3M Oral Care, Maplewood, MN). Immediately remove the resulting molded dish from the mold and place it into a 2 mL plastic centrifuge tube containing 1.5 mL of GIBCO phosphate-buffered saline (PBS) solution (1X, pH 7.4) (Thermo Fisher Scientific). Completely immerse the dish in the PBS solution. Cap the tube and store at room temperature.

[0281] For dental composition 2 (DC-2), paste B2 replaces paste B1 as the first part of the composition. A molded disc is prepared using DC-2 according to the process described for DC-1. The pH of the paste, measured immediately before filling the mold, is 3.8.

[0282] For dental composition 3 (DC-3), paste B3 replaces paste B1 as the first part of the composition. A molded disc is prepared using DC-3 according to the process described for dental composition 1. The pH of the paste, measured immediately before filling the mold, is 3.7.

[0283] For dental composition 4 (DC-4), paste B4 replaces paste B1 as the first part of the composition. A molded disc is prepared using DC-4 according to the process described for DC-1. The pH of the paste, measured immediately before filling the mold, is 3.6.

[0284] For dental composition 5 (DC-5), paste B5 replaces paste B1 as the first part of the composition. A molded disc is prepared using DC-5 according to the process described for DC-1. The pH of the paste, measured immediately before filling the mold, is 4.9.

[0285] For dental composition 6 (DC-6), paste B6 replaces paste B1 as the first part of the composition. A molded disc is prepared using DC-6 according to the process described for DC-1. The pH of the paste, measured immediately before filling the mold, is 3.8.

[0286] For comparative dental composition A (comparative DC-A), paste BA replaces paste B1 as the first part of the composition. Paste BA does not contain encapsulating material. A molded disc is prepared using comparative DC-A according to the process described for DC-1. The pH of the paste, measured immediately before filling the mold, is 3.6.

[0287] For each immersed disc, the pH of the PBS solution was measured periodically over 364 hours using an ORION PERPHECT ROSS pH microelectrode (catalog number 8220BNWP, Thermo Fisher Scientific Company). The sample was gently shaken before each measurement. The pH profiles of the PBS solution are reported in Tables 15 and 16. pH measurements recorded at “0 h” were performed immediately after the disc was immersed in the PBS solution.

[0288] In Table 15, the concentration (wt%) of encapsulating material H incorporated into the dental compositions decreases from DC-1 to DC-4, with control DC-A not containing encapsulating material H. (That is, the concentration of encapsulating material incorporated is DC-1 > DC-2 > ​​DC-3 > DC-4 > control DC-A.) In Table 16, the shell thickness of the encapsulating material in dental compositions DC-1, DC-5, and DC-6 is different, with DC-6 containing the encapsulating material with the thickest shell and DC-5 containing the encapsulating material with the thinnest shell.

[0289] Table 12: Composition of Paste A

[0290] Components Weight percentage of the composition (wt%) Hydroxyethyl methacrylate (HEMA) 12.07 Butylated hydroxytoluene (BHT) 0.03 Camphorquinone (CPQ) 0.33 Deionized water 22.01 VBP 25.83 Calcium glycerol phosphate 4.57 Zr / Si nanocluster filler 30.14 Ytterbium fluoride 5.02

[0291] Table 13: Compositions of pastes B1-B4 (pastes containing varying amounts of encapsulating material H) and paste BA

[0292]

[0293] Table 14: Compositions of pastes B1, B5, and B6 (using bioactive glass cores with varying thicknesses) (Paste prepared from the encapsulating material of the alumina shell)

[0294]

[0295] Table 15: Dental compositions with encapsulating materials H of varying concentrations (wt%) from DC-1 to DC-4 pH measurement of PBS solution in contact with the prepared molded tray

[0296]

[0297] Table 16: Dental compositions made from DC-1, DC-5, and DC-6 (containing encapsulating materials with different shell thicknesses) pH measurement of PBS solution in contact with the prepared molded tray

[0298]

[0299] NT = Untested

[0300] Example 15: Dental composition of material with Portland cement encapsulation

[0301] Dental compositions (DC-7 to DC-11) were prepared using a paste selected from pastes B7-B11 as the first part of the composition and paste A as the second part of the composition.

[0302] Paste A was prepared as reported in Example 14.

[0303] The compositions of pastes B7-B9 are reported in Table 17 (each component is reported in wt%). Pastes B7-B9 were prepared by adding EDMAB to a flask containing HEMA and mixing. In a separate beaker, FAS glass, encapsulating material P (from Table 3), and pyrolytic silica were mixed to form a homogeneous mixture. The EDMAB / HEMA mixture was then added to the mixture in the beaker, and the contents were stirred until homogeneous. The beaker was covered, and the paste was used within 24 hours of preparation.

[0304] The composition of paste B10 is reported in Table 18. Paste B10 was prepared according to the general method described above for pastes B7-B9, except that the encapsulating material P was replaced with the encapsulating material of Example 4 (titanium dioxide-encapsulated Portland adhesive).

[0305] The composition of paste B11 is reported in Table 19. Paste B11 was prepared according to the general method described above for pastes B7-B9, except that the encapsulating material P was replaced with the encapsulating material of Example 5 (silica-encapsulated Portland adhesive).

[0306] For dental composition 7 (DC-7), paste B7 is the first part of the composition. Combine paste A and paste B7 of DC-7 (1:1 by weight) on a mixing pad and scrape until homogeneous (mixing for approximately 10–30 seconds). Immediately measure the pH of the resulting paste using an ORIONPERPHECT ROSS pH microelectrode (catalog number 8220BNWP, Thermo Fisher Scientific Company). Record the pH reading 30 seconds after inserting the probe into the paste. The recorded pH is 3.5. Immediately fill a Teflon disc mold (3.1 mm diameter and 1.3 mm height) with the paste and then cure for 20 seconds on each side of the mold using an ELIPARS10 curing light (3M Oral Care, Maplewood, MN). Immediately remove the resulting molded dish from the mold and place it into a 2 mL plastic centrifuge tube containing 1.5 mL of GIBCO phosphate-buffered saline (PBS) solution (1X, pH 7.4) (Thermo Fisher Scientific). Completely immerse the dish in the PBS solution. Cap the tube and store at room temperature.

[0307] For dental composition 8 (DC-8), paste B8 replaces paste B7 as the first part of the composition. A molded disc is prepared using DC-8 according to the process described for DC-7. The pH of the paste, measured immediately before filling the mold, is 3.5.

[0308] For dental composition 9 (DC-9), paste B9 replaces paste B7 as the first part of the composition. A molded disc is prepared using DC-9 according to the process described for DC-7. The pH of the paste, measured immediately before filling the mold, is 3.6.

[0309] For dental composition 10 (DC-10), paste B10 replaces paste B7 as the first part of the composition. A molded disc is prepared using DC-10 according to the process described for DC-7. The pH of the paste, measured immediately before filling the mold, is 3.3.

[0310] For dental composition 11 (DC-11), paste B11 replaces paste B7 as the first part of the composition. A molded disc is prepared using DC-11 according to the process described for DC-7. The pH of the paste, measured immediately before filling the mold, is 3.3.

[0311] For each immersed disc, the pH of the PBS solution was measured periodically over 333 or 646 hours using an ORION PERPHECT ROSS pH microelectrode (catalog number 8220BNWP, Thermo Fisher Scientific Company). The sample was gently shaken before each measurement. The pH profiles of the PBS solution are reported in Tables 20 and 21. pH measurements recorded at “0 h” were performed immediately after the disc was immersed in the PBS solution.

[0312] Table 20 evaluates dental compositions with varying concentrations of incorporating encapsulating material P. DC-7 contains approximately twice the amount of encapsulating material P (based on weight %) as DC-9. DC-A, in contrast, does not contain encapsulating material P.

[0313] Table 17: Compositions of pastes B7-B9 (pastes containing varying amounts of encapsulating material P)

[0314]

[0315] Table 18: Composition of Paste B10 (containing the encapsulating material of Example 4)

[0316] Components Weight percentage of the composition (wt%) Hydroxyethyl methacrylate (HEMA) 33.7 Ethyl ethyl-4-dimethylaminobenzoate (EDMAB) 0.3 FAS glass 16.25 <![CDATA[Encapsulated material of Example 4 (core: PC, shell: TiO2)]]> 48.75 Pyrolysis of silicon dioxide 1.0

[0317] Table 19: Composition of Paste B11 (containing the encapsulating material of Example 5)

[0318] Components Weight percentage of the composition (wt%) Hydroxyethyl methacrylate (HEMA) 33.7 Ethyl ethyl-4-dimethylaminobenzoate (EDMAB) 0.3 FAS glass 16.25 <![CDATA[Encapsulated material of Example 5 (core: PC, shell: SiO2)]]> 48.75 Pyrolysis of silicon dioxide 1.0

[0319] Table 20: Dental compositions with encapsulated materials P consisting of DC-7 and DC-9 (with varying concentrations (wt%)) pH measurement of PBS solution in contact with the prepared molded disc

[0320]

[0321] Table 21: Dental combinations with DC-8, DC-10, and DC-11 (materials with different shell materials) pH measurement of PBS solution in contact with a molded disc prepared by (material)

[0322]

[0323] Example 16: Dental composition of a material encapsulated with tricalcium silicate

[0324] A molded disc was prepared using dental composition DC-12 according to the procedure reported in Example 14. Paste B12 (the composition in Table 22) was used as the first part of the composition, and paste A was used as the second part to prepare DC-12. The pH of the scraped paste, measured immediately before filling the mold, was 3.7. The pH of the PBS solution surrounding the disc was periodically measured for 790 hours according to the procedure described in Example 14 and the results reported in Table 23. The pH measurement, recorded at “0 hours,” was performed immediately after the disc was immersed in the PBS solution.

[0325] Table 22: Composition of Paste B12 (including encapsulating material K)

[0326] Components Weight percentage of the composition (wt%) Hydroxyethyl methacrylate (HEMA) 33.7 Ethyl ethyl-4-dimethylaminobenzoate (EDMAB) 0.3 FAS glass 16.25 Encapsulation material K (from Table 2, core: TCS, shell: AO) 48.75 Pyrolysis of silicon dioxide 1.0

[0327] Table 23: Contact material from DC-12 [including encapsulated material K (tricalcium silicate core and alumina shell)] in contact with the molded disc pH measurement of PBS solution prepared from dental composition

[0328]

[0329] Example 17: Cell proliferation of dental pulp stem cells in contact with a dental composition comprising encapsulated bioactive glass colony

[0330] Molded discs (3.1 mm in diameter and 1.3 mm in height) for dental compositions 1-4 and comparative dental composition A were prepared using the general mixing and curing process for preparing the molded discs described in Example 14. Individual discs were also prepared from commercially available dental base / lining products (Comparative Example X) and commercially available pulp cap / lining products (Comparative Example Y). Discs were individually sterilized by sequentially placing them in a 70% ethanol bath for 20 minutes, rinsing with PBS (3 times), and then incubating overnight in dental pulp stem cell (DPSC) basal medium (Lonza Group LTD., Basel, Switzerland) (37°C, 5% CO2, 98% relative humidity). Human dental pulp stem cells (DPSC, Lonza Group LTD.) were seeded at 20,000 cells / mL / well in a Costar 48-well cell culture plate containing DPSC basal medium (Corning Incorporated, Corning, NY). Each well was loaded with a tray and cultured for seven days (37°C, 5% CO2, 98% relative humidity). As a control, additional wells were seeded with human dental pulp stem cells, but no molded trays were added to any of these wells.

[0331] On day 7, cell proliferation of DPSC samples was assessed using an MTT assay kit (Invitrogen Corporation, Carlsbad, CA), with absorbance measured at 540 nm using a microplate reader (Tecan Group LTD., Mannedorf, Switzerland). Table 24 records the mean OD540 (n=6) of DPSC samples in contact with dental compositions 1-4 (containing varying concentrations of encapsulated bioactive glass material), control dental composition A (without encapsulation material), comparative examples X and Y, and the control.

[0332] Table 24: Cell proliferation of dental pulp stem cells

[0333]

[0334] Example 18: Teeth in contact with dental compositions comprising encapsulated Portland cement or encapsulated tricalcium silicate Cell proliferation of myeloid stem cells

[0335] Molded discs (3.1 mm diameter and 1.3 mm height) for dental compositions 8, 10, 11, 12, control dental composition A, comparative example X, and comparative example Y were prepared, and cell proliferation was tested according to the procedure described in Example 17. Control examples (using DPSC seeding wells but without molded discs) were also prepared as described in Example 17. In Table 25, the average OD540 (n = 4) of DPSC samples in contact with dental compositions 8, 10, 11, 12 (containing encapsulated materials with Portland cement or tricalcium silicate cores having different shell coatings), control dental composition A (without encapsulated materials), comparative examples X and Y, and control examples are recorded.

[0336] Table 25: Cell proliferation of dental pulp stem cells

[0337]

[0338] Example 19: ALP activity of dental pulp stem cells in contact with dental composition

[0339] The molded discs (3.1 mm diameter and 1.3 mm height) for dental compositions 1-4 and comparative dental composition A were prepared using the general mixing and curing process for preparing the molded discs described in Example 14. The discs were individually sterilized by sequentially placing them in a 70% ethanol bath for 20 minutes, rinsing with PBS (3 times), and then incubating overnight in dental pulp stem cell (DPSC) basal medium (Lonza Group LTD.) (37°C, 5% CO2, 98% relative humidity). Human dental pulp cells (DPSC, Lonza Group LTD.) were seeded at 20,000 cells / mL / well in COSTAR 48-well cell culture plates containing DPSC basal medium (Corning Incorporated, Corning, NY). Each well was loaded with a disc, and the cells were cultured for seven days (37°C, 5% CO2, 98% relative humidity). As a control, human dental pulp stem cells were seeded into additional wells, but no molded disc was added to any of these wells.

[0340] On day 7, DPSC cells were collected, and the alkaline phosphatase (ALP) activity of the cell lysate in each sample was analyzed using a human ALP ELISA kit (BioVision Incorporated, San Francisco, CA) according to the manufacturer's instructions. Table 26 records the mean ALP concentration (n=2) of the DPSC samples in contact with dental compositions 1-4 (containing varying concentrations of encapsulated bioactive glass material), control dental composition A (not containing encapsulated material), comparison X and comparison Y, and the control, in mU / mL.

[0341] Table 26: Alkaline phosphatase (ALP) activity

[0342]

[0343] Example 20: ALP activity of dental pulp stem cells in contact with dental composition

[0344] Molded discs (3.1 mm diameter and 1.3 mm height) for dental compositions 8, 10, 11, 12, comparative dental composition A, comparative example X, and comparative example Y were prepared, and ALP activity was tested according to the procedure described in Example 19. A control example (using DPSC inoculation wells but without a molded disc) was also prepared as described in Example 19. In Table 27, the average ALP concentrations (n ​​= 1-3) of the DPSC samples in contact with dental compositions 8, 10, 11, 12 (containing encapsulated materials with Portland cement or tricalcium silicate cores having different shell coatings), comparative dental composition A (without encapsulated materials), comparative examples X and Y, and the control examples are recorded in mU / mL.

[0345] Table 27: Alkaline phosphatase (ALP) activity

[0346]

[0347] Example 21: Encapsulation material with calcium hydroxide core or mixed-phase calcium silicate core

[0348] Calcium hydroxide (CH) powder was obtained from Jost Chemical (St. Louis, Missouri, product number: 2242). The material was sieved through a 25-micron sieve.

[0349] Mixed-phase calcium silicate (MPCS) was prepared by mixing 14.1 wt% SiO2, 50.3 wt% CaCO3, 34.7 wt% H2O, and 0.8 wt% BYK-W9012. The BYK-W9012 wetting and dispersing additive was obtained from BYK-Chemie GmbH, Wesel, Germany. After mixing, the resulting paste was dried at 100 °C for 12 hours and then sintered at 1500 °C for two hours. The resulting particles were ground using a mortar and pestle to provide a powder with a measured average particle size of 11.35 μm by laser diffraction.

[0350] Using the APCVD method and apparatus described in Example 2, calcium hydroxide (CH) and mixed-phase calcium silicate (MPCS) were individually encapsulated with alumina, except that a heating belt was used to heat the reactor, and the powder amount and flow rate were reported in Table 28.

[0351] Table 28: CH and MPCS encapsulated using APCVD method

[0352]

[0353] Example 22: pH buffering test of the encapsulated material

[0354] Unencapsulated CH and MPCS samples from the batches described in Table 28, as well as encapsulated CH and MPCS, were tested as described in Example 6. The pH of the buffer solution for all four samples was exactly 4.1 before the powder was added. The results are given in Table 29, and the results show that the encapsulation material provides a delayed reaction with the alkaline core material or a delayed release of the alkaline core material.

[0355] Table 29: pH Measurements of CH and MPSC Samples from Example 28

[0356]

[0357] Example 23: Portland adhesive core encapsulated using atomic layer deposition (ALD)

[0358] Portland binder powder (5) was microencapsulated using atomic layer deposition (ALD). An alumina coating was deposited by self-limiting surface reaction of oriented particulate material using a flow-through atomic layer deposition (FTALD) reactor comprising a sequential four-step process (precursor A, purge, precursor B, purge).

[0359] The continuous 4-step method consisted of the following sequence: (1) precursor A (i.e., trimethylaluminum (TMA)) pulse, (2) N2 purging, (3) precursor B (i.e., ozone @ 20% pulse), and (4) N2 purging. The TMA precursor pulse duration and pressure were set to 1.125 seconds at a pressure of 1 to 3 Torr inside the reactor. The ozone precursor pulse duration and pressure were set to 1.000 seconds at a pressure of 1 to 4 Torr inside the reactor. The purging time was in the range of 100 to 120 seconds per half-cycle. The 4-step sequence is referred to herein as one ALD cycle. 5g samples of Portland adhesive were treated with a total of 200 ALD cycles at a processing temperature of 150°C.

[0360] The internal sample chamber consists of a 34mm sintered tube, one end of which is closed, and the other open end is equipped with a fitting (VCR8 fitting). The fitting is then attached to a precursor delivery system, which allows the addition of various gases to flow into the interior of the sintered tube and exit through the wall of the sintered tube.

[0361] The precursor delivery system is designed with a rotary joint, allowing the sintering tube (sample chamber) to rotate independently of the rest of the reactor system. The sintering tube, attached to the precursor delivery system, is then placed inside a temperature control sleeve or tube to control the temperature of the particles and precursor during the deposition process.

[0362] During the deposition process, the tube containing the particles is rotated, causing the particles to be lifted along the tube wall and fall freely back to the bottom of the tube. During this free fall, the particles sequentially contact various precursors and purging steps as gas flows into the open end of the sintering tube and exits through the wall. A vibratory motor is also attached to the reactor assembly to provide additional agitation to keep the particles free-flowing during the deposition process. All gases are heated to 80°C to ensure the gas flow does not cool the sample.

[0363] The precursor feed was monitored using a residual gas analyzer (trade name "SRS RESIDUAL GAS Analyzer", available from Stanford Research Systems, Inc., Sunnyvale, CA) to ensure that sufficient precursors were delivered to the reactor.

[0364] The pH change of the encapsulated powder was measured using the process described in Example 6. The results are reported in Table 30.

[0365] Table 30: pH Measurement of Portland Adhesive Encapsulated with ALD

[0366]

[0367] Example 24: Cementation of dental composition 8 (DC-8) and comparative dental composition A (DC-A) applied to the tooth surface Adhesion measurement .

[0368] Bovine incisors (10) were embedded in resin discs with a diameter of 25 mm and a height of 10–20 mm (one tooth per pound). Each resulting disc was ground with 120 grit sandpaper to contact the dentin layer of the tooth and polished with 320 grit sandpaper. All experiments were conducted in a chamber at a constant temperature of 75°C and humidity of 50%, with light filtered at 450 nm. Each tooth surface was blotted dry to remove excess water, and a 5 mm diameter circle of contact dentin was outlined using 3M 201+ masking tape (3M Company, Maplewood, MN) as a mask. DC-8 (prepared as described in Example 15) was applied to cover the contact dentin area, the mask was smoothed with a scraper, and then cured for 20 seconds using an ELIPAR S10 LED curing lamp (3M Company). SCOTCHBOND general-purpose adhesive (3M Company) was then applied to the cured surface for 20 seconds using a disposable applicator. The site was dried with a gentle airflow for 5 seconds, and then cured with an ELIPAR S10 LED curing light for 10 seconds. A Teflon mask (2-5 mm deep with a 5 mm diameter hole marked with white gelatin) was aligned with the mask and secured with a metal clip. The hole was then filled with FILTEK Z250 dental composite resin (3M Company) and cured with an ELIPAR S10 LED curing light for 20 seconds to form a post. The tooth sample was then placed in a room (37°C and 95% humidity) for 0.5 hours. The metal clip was removed from the tooth sample, and each sample was immersed in deionized water at 37°C for 24 hours. After 24 hours, the white gelatin dissolved, and the Teflon mask was removed. The resin disc was secured in a circular clamp on the upper arm of an Instron 5944 (Instron Corporation, Norwood, MA). The lower clamp has a wire loop approximately 90 mm long. The thread is wrapped around the FILTEK Z250 post and secured flush with the tooth / resin surface. Tension is applied until failure (i.e., the component breaks off from the tooth surface or the tooth breaks) to determine the adhesion of the cured dental composition DC-8 to the tooth.

[0369] The procedure was repeated using comparative dental composition A (such as DC-A prepared in Example 14) instead of DC-8. The average (n=10) adhesion values ​​(MPa) of dental compositions DC-A and DC-8 were measured and reported in Table 31.

[0370] Table 31: Adhesion measurements of dental compositions DC-8 and DC-A to tooth enamel .

[0371] Dental Composition Average adhesion (MPa) (n=10) Standard deviation (MPa) DC-8 10.09 2.74 DC-A 8.11 2.10

[0372] Example 25: Dental Composition (DC-13)

[0373] Dental composition B (DC-B) was prepared by adding 120 mg of IRGACURE 819 (a photoinitiator from BASF Corporation, Wyandotte, MI) to 40 g of SR 603 (polyethylene glycol (400) dimethacrylate from Sartomer Americas, Exton, PA). The mixture was mixed three times at 3000 rpm for 1 minute in a FlackTek DAC 150 FVZ speed mixer. The DC-B was immediately filled into a Teflon disc mold (3.1 mm diameter and 1.3 mm height) and then used with Elipare. TM The DeepCure-S LED curing lamp (3M Corporation) was used to cure the mold for 20 seconds on each side. The resulting molded disc was immediately removed from the mold and placed in a 2 mL plastic centrifuge tube containing 1.5 mL of GIBCO phosphate-buffered saline (PBS) solution (1X, pH 7.4) (Thermo Fisher Scientific). The disc was completely submerged in the PBS solution. The tube was capped and stored at room temperature. The disc from dental composition B was used as a control (excluding encapsulating material).

[0374] Dental composition 13 (DC-13) was prepared by combining 3g of encapsulating material P with 1g of DC-B. The mixture was stirred three times at 3000rpm for 1 minute. A molded disc was prepared using DC-13 according to the process described for DC-B.

[0375] Dental composition C (DC-C) was prepared by combining 3g of unencapsulated Portland cement with 1g of DC-B. The mixture was stirred three times at 3000rpm for 1 minute. Molded discs were prepared using DC-C according to the process described for DC-B. Discs from dental composition C were used as a control (including unencapsulated Portland cement).

[0376] For each immersed dish, the pH of the PBS solution was measured periodically over a period of 90.4 hours using an ORION PERPHECT ROSS pH microelectrode (catalog number 8220BNWP, Thermo Fisher Scientific Company). Each sample was gently shaken before each measurement. The pH profiles of the PBS solutions are reported in Table 32. pH measurements recorded at “0 h” were performed immediately after the dish was immersed in the PBS solution.

[0377] Table 32: pH measurements of PBS solutions in contact with molded discs prepared from DC-13, DC-B, and DC-C 。

[0378]

Claims

1. A dental composition comprising: The encapsulating material comprises: The core, comprising Portland adhesive, and The housing contains a metal oxide. The housing surrounds the core, and The shell degrades, dissolves, or decomposes upon contact with water or acidic components to release the core, thereby increasing the pH.

2. The dental composition according to claim 1, wherein the housing is a continuous film having a thickness of less than 500 nm.

3. The dental composition according to claim 1, wherein the metal oxide is characterized by a pKa of 6-8.

4. The dental composition of claim 1, wherein the core further comprises a source of phosphorus ions, fluoride ions, or combinations thereof.

5. The dental composition according to claim 1, wherein the dental composition further comprises nanoscale particulate filler or nanocluster filler.

6. The dental composition of claim 5, wherein the nanoscale microparticle filler comprises zirconium oxide, silicon dioxide, or a combination thereof.

7. The dental composition of claim 1, further comprising a polymerizable material selected from hydroxyl-functional (meth)acrylate monomers, acid polymers, or combinations thereof.

8. A two-part composition, said two-part composition comprising: The dental composition according to any one of the preceding claims; and Water or acidic components.

9. The two-part composition of claim 8, wherein when the dental composition is exposed to water or the acidic component, the encapsulating material raises the pH of the water more slowly than when the contents of the core are exposed to water alone.

10. A method for preparing the encapsulating material according to claim 1, the method comprising: Portland adhesives are available. Provide metal oxides; as well as The Portland adhesive is encapsulated with the metal oxide using at least one vapor deposition technique.

11. Use of the dental composition according to any one of claims 1-7 in the manufacture of a medicament for increasing the average alkaline phosphatase activity of dental pulp cells, remineralizing teeth, or a combination thereof.

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