glass composition

Abstract

The purpose of this disclosure is to provide a glass composition for dentin desensitization compositions. [Solution] This disclosure provides a glass composition comprising about 50 mol% to about 95 mol% of B2O3; and about 5 mol% to about 50 mol% of one or more glass components selected from the group consisting of Li2O, Rb2O, K2O, Na2O, SrO, CaO, MgO, and ZnO. The glass composition contains less than 30 mol% of Rb2O. The glass composition is a four-component system. The glass composition is particulate matter containing particles with a size of about 1 to about 50 μm. When exposed to a buffered saline solution, the glass composition loses at least 5% by mass within 24 hours. The glass composition can be used to desensitize dentin. This disclosure also provides a dentin desensitization composition.

Description

[Technical Field]

[0001] This disclosure relates to a glass composition for dentin desensitization compositions. [Background technology]

[0002] The following paragraphs do not constitute an admission that what is discussed therein is part of the prior art or the knowledge of a person skilled in the art.

[0003] Dentin sensitivity is tooth pain resulting from an exposed dentin surface in response to thermal, evaporative, tactile, osmotic, chemical, or electrical stimuli. Dentin sensitivity can be caused by gingival recession (receding gingiva) with exposure of the root surface, loss of the cementum and plaster layer, tooth wear, acid erosion, root flattening, or tooth whitening.

[0004] Dentin has thousands of tiny tubular structures that radiate outward from the pulp. Changes in the flow of plasma-like fluid within the dentinal tubules trigger mechanoreceptors in the nerves on the pulp side, thereby causing a pain response. This hydrodynamic flow can be increased by cold air, dryness, sugar, acidity (dehydrating chemicals), or forces acting on the tooth. Hot or cold foods and drinks, and physical pressure are typical triggers for people with sensitive teeth.

[0005] There is no globally accepted gold standard treatment that reliably relieves the pain of dental hypersensitivity in the long term. However, treatment can be divided into treatments that can be performed in a clinic (i.e., intended to be applied by a dentist or dental therapist) or at home, with over-the-counter medications, or with a prescription.

[0006] The mechanisms of action of these treatments are thought to be either occlusion of dentinal tubules or desensitization of nerve fibers / blockage of neurotransmission. [Overview of the Initiative]

[0007] introduction The following introduction is intended to introduce the reader to this specification but does not define any invention. One or more inventions may be found in combinations or subcombinations of apparatus elements or method steps described below, or in other parts of this specification. The inventors do not waive or abandon any rights to the inventions disclosed herein solely by not claiming such other inventions.

[0008] An example of a dentin desensitization composition known in the art is disclosed in PCT Publication WO2007144662A1. The disclosed toothpaste contains a strontium-containing bioactive glass. The disclosed bioactive glass occludes dentin tubules and induces the precipitation and crystallization of carbonated hydroxyapatite. The disclosed bioactive glass is designed to degrade at the same rate as the induced intratissue growth.

[0009] An example of a dentin desensitizing composition known in the art is disclosed in U.S. Patent 5,735,942. The disclosed toothpaste contains mineral components consisting of CaO, Na2O, P2O5, and SiO2. The disclosed mineral composition chemically reacts with the surface of dentin and forms a close bond with the tooth structure.

[0010] One or more of the described embodiments attempt to address or improve upon one or more drawbacks associated with dentin desensitization compositions comprising non-degradable particulate material that occludes dentinal tubules. In some embodiments, the disclosed particulate matter substantially degrades over 12 to 24 hours under environmental conditions. In some embodiments, the disclosed particulate matter provides controlled fluoride release over the same period.

[0011] In some embodiments, the disclosure provides a glass composition comprising about 50 mol% to about 5 mol% of a glass component selected from the group consisting of Li2O, Rb2O, K2O, Na2O, SrO, CaO, MgO, ZnO and any combination thereof; 0 mol% of CuO; less than 0.1 mol% of BaO; and less than 0.1 mol% of P2O5, wherein the glass composition comprises less than 30 mol% of Rb2O; the glass composition loses at least 5 mol% within 24 hours upon exposure to a buffered saline solution; and the glass composition is a particulate material comprising particles of about 1 to about 50 μm in size. The glass composition is not composed solely of B2O3 and Na2O.

[0012] In some examples of glass compositions according to this disclosure, the glass composition present in amounts less than 20 mol%, for example less than 15 mol, less than 10 mol, or less than 5 mol%, is CaO, MgO, and Na2O.

[0013] The glass composition may further contain up to about 30 mol% of fluoride, where the fluoride is in the form of CaF2, NaF, Na2PO3F, KF, or SnF2.

[0014] In other embodiments, the disclosure provides a glass composition for desensitizing dentin, the glass composition comprising about 50 mol% to about 95 mol% of glass components selected from the group consisting of about 50 mol% to about 95 mol% of B2O3;Li2O, Rb2O, K2O, Na2O, SrO, CaO, MgO, ZnO, and any combination thereof, wherein the glass composition comprises less than 30 mol% of Rb2O. The glass composition loses at least 5% by mass within 24 hours upon exposure to buffered saline, and the glass composition is a particulate material comprising particles of about 1 to about 50 μm in size.

[0015] In some examples of glass compositions, the glass compositions present in less than 20 mol%, for example, less than 15 mol, less than 10 mol, or less than 5 mol%, are CaO, MgO, and Na2O.

[0016] The glass composition may further contain up to about 30 mol% fluoride, where the fluoride is in the form of CaF2, NaF, Na2PO3F, KF, or SnF2.

[0017] In other embodiments, the present disclosure provides a fluoride provided as about 5 mol% to about 10 mol% of CaF2, SnF2, NaF, KF, or any combination thereof; and a glass composition comprising a combination of about 9 mol% to about 95 mol% of B2O3, Na2O, MgO, and CaO, where the boron, magnesium, the combination of Na and any K, and the combination of Ca and any Sn in the glass composition are present in elemental ratios of about 20: about 4: about 6: about 3, respectively.

[0018] An example of such a specific glass composition according to the present disclosure contains about 50 mol% of B2O3, about 15 mol% of Na2O, about 20 mol% of MgO, about 10 mol% of CaO, and about 5 mol% of CaF2.

[0019] The glass composition according to the present disclosure can be formulated into a dentin desensitizing composition such as toothpaste, preventive paste, dental varnish, mouthwash, dental gel, or adhesive. The dentin-desensitizing composition according to the present disclosure is substantially anhydrous.

[0020] The glass composition according to the present disclosure can be used to desensitize dentin in a method, for example, including applying a toothpaste, preventive paste, dental varnish, mouthwash, dental gel, or adhesive according to the present disclosure to an individual's dentin.

[0021] The glass composition according to the present disclosure can be prepared from the corresponding bulk glass. The chemical formulation is the same between the bulk glass and the particulate material. Another aspect of the present disclosure is a bulk glass having a chemical formulation as disclosed herein.

[0022] Here, embodiments of the present disclosure will be described by way of example only with reference to the accompanying drawings.

Brief Description of the Drawings

[0023] [Figure 1] Figure 1 shows the average of the surface profiles of resin composites after 20,000 brushing cycles of gel 7HT toothpaste (the "gel") formulated with the glass composition of the present disclosure (the "gel + additive") against gel 7HT toothpaste (the "gel"). [Figure 2] Figure 2 shows the average of the surface profiles of resin composites after 20,000 brushing cycles of Gel7HT (the "Gel") toothpaste formulated with the glass composition (the "Colgate EN + additive") against Colgate (trademark) Enamel Health Sensitivity Relief (trademark) toothpaste. [Figure 3] Figure 3 is a diagram showing the average of the surface profiles of resin composites after 20,000 brushing cycles using Gel7HT toothpaste (the "Gel") against Colgate (trademark) Optic White (trademark) toothpaste (the "Colgate Optic"). [Figure 4] Figure 4 is a diagram showing the average of the surface profiles of resin composite resin after 20,000 brushing cycles of Gel7HT (the "Gel") toothpaste against Colgate (trademark) Enamel Health Sensitivity Relief (trademark) toothpaste (the "Colgate EN"). [Figure 5] Figure 5 is a diagram showing the average of the surface profiles of resin composites after 20,000 brushing cycles using Gel7HT toothpaste (the "Gel") and Sensodyne (trademark) Whitening Repair and Protect (trademark) toothpaste (the "Sensodyne"). [Figure 6] Figure 6 shows the average of the surface profiles of the enamel surface after 20,000 brushing cycles of Gel7HT toothpaste (the "Sensodyne") formulated with the glass composition (the "gel + additive") against Sensodyne (trademark) Whitening Repair and Protect (trademark) toothpaste (the "Sensodyne"). [Figure 7]Figure 7 shows the average surface profiles of enamel surfaces after 20,000 brushing cycles using Gel7HT toothpaste formulated with the glass composition ("Gel+ Additive") versus Colgate® Enamel Health Sensitivity Relief® toothpaste formulated with the glass composition ("Colgate EN+ Additive"). [Figure 8] Figure 8 shows the average surface profile of the enamel surface after 20,000 brushing cycles for Gel 7HT toothpaste ("Gel") formulated with a glass composition ("Gel + Additives") and Gel 7HT toothpaste. [Figure 9] Figure 9 shows the average surface profile of the enamel surface after 20,000 brushing cycles using Gel7HT toothpaste formulated with Colgate® Optic White® toothpaste ("Colgate Optic") versus a glass composition ("Gel + Additives"). [Figure 10] Figure 10 shows the average surface profile of the enamel surface after 20,000 brushing cycles using Gel7HT toothpaste formulated with Colgate® Enamel Health Sensitivity Relief® toothpaste ("Colgate EN") versus a glass composition ("Gel + Additives"). [Figure 11] Figure 11 shows scanning electron microscope images of the exemplary glass composition of this disclosure after 30 minutes at 37°C in simulated body fluid (SBF). [Figure 12] Figure 12 shows scanning electron microscope images of exemplary glass compositions according to this disclosure after 3 hours in simulated body fluid (SBF) at 37°C. [Figure 13] Figure 13 shows scanning electron microscope images of exemplary glass compositions according to this disclosure after 12 hours in simulated body fluid (SBF) at 37°C. [Figure 14] Figure 14 is another scanning electron microscope image of an exemplary glass composition according to this disclosure after 12 hours in simulated body fluid (SBF) at 37°C. [Modes for carrying out the invention]

[0024] The glass composition according to this disclosure is at least a four-component system. The glass composition contains about 50 mol% to about 95 mol% of B2O3; and about 5 mol% to about 50 mol% of one or more glass components selected from the group consisting of Li2O, Rb2O, K2O, Na2O, SrO, CaO, MgO, and ZnO. The glass composition contains less than 30 mol% of Rb2O. The glass composition according to this disclosure decomposes under physiological conditions and loses at least 5% by mass within 24 hours upon exposure to buffered saline.

[0025] The glass composition is a particulate matter containing particles of a size of approximately 1 to approximately 50 μm. The glass composition contains at least some particles of a size that obstructs dentinal tubules, thereby desensitizing the dentin. In the context of this disclosure, particles of a size that obstructs dentinal tubules should be understood to mean particles that are present in or above the dentinal tubules, reducing the movement of dentinal fluid.

[0026] In the context of this disclosure, a glass composition that is “at least four-component” should be understood to refer to glass having four or more distinct elements. For example, since glass contains boron, lithium, zinc, and oxygen, a glass composition consisting only of B2O3, Li2O, and ZnO is considered a four-component system. Similarly, since glass contains boron, calcium, fluorine, and oxygen, a glass composition consisting only of B2O3, CaO, and CaF2 is considered a four-component system. In contrast, a glass composition consisting only of B2O3 and Na2O is considered a three-component system because it contains the elements boron, sodium, and oxygen.

[0027] It should be understood that "approximately 5 mol% to approximately 50 mol% of one or more glass components" refers to the total mol% of the glass components, and not to the mol% of each individual component. For example, the glass composition according to this disclosure may contain 2.5 mol% Li2O and 2.5 mol% ZnO to provide the enumerated 5 mol% of additional glass components.

[0028] Please understand that "approximately X mol%" refers to a value within ±2% of the reported percentage. For example, "approximately 10 mol%" refers to a value between 8 mol% and 12 mol%, because all of these values ​​are within ±2% of the reported 10%; "approximately 50 mol%" refers to a value between 48 mol% and 52 mol%, because all of these values ​​are within ±2% of the reported 50%.

[0029] It should be understood that "approximately X μm" in the context of particle size is determined based on the acceptable tolerance according to ASTM for the size of the test sieve of interest. For example, the acceptable tolerance for a 50 μm test sieve is 3 μm. Therefore, "approximately 50 μm" refers to particles with a size of 47 μm to 53 μm. In another example, the acceptable tolerance for a 35 μm test sieve is 2.6 μm. Therefore, "approximately 35 μm" refers to particles with a size of 32.4 μm to 38.6 μm. The ASTM acceptable tolerance for a 25 μm sieve is 2.2 μm. For standard test sieves without tolerances (e.g., test sieves less than 20 μm), the expression "approximately X μm" refers to ±15% for sizes between 5 and 15 μm, and ±50% for sizes less than 5 μm. For example, "approximately 1 μm" refers to particles with a size of 0.5 to 1.5 μm.

[0030] glass composition The glass compositions according to this disclosure may contain fluoride sources such as CaF2, NaF, Na2PO3F, KF, or SnF2. When fluoride is included in a glass composition, it is released as the glass degrades. The released fluoride forms fluorapatite (Ca5(PO4)3F) in or around the dentinal tubules, forming a protective precipitate and further reducing dentin sensitivity. In a fluoride-containing glass composition, the fluoride source may be up to 30 mol% of the glass composition. In some examples, the fluoride source may be about 1 mol% to about 10 mol% of the glass composition, for example, about 1 mol% to about 5 mol%. In certain examples, the fluoride source is about 15 mol% of the composition. Compositions containing CaF2 or SnF2 have twice the amount of fluoride per mole of starting material compared to compositions using NaF, Na2PO3F, or KF.

[0031] In some examples, the glass composition contains about 1 mol% to about 10 mol% of fluoride. In other examples, the glass composition contains about 1 mol% to about 5 mol% of fluoride.

[0032] In some examples, the glass composition contains enough fluoride for 0.1 g of particulate matter to release fluoride into 10 mL of buffered saline at an average rate of about 1 ppm / hr to about 15 ppm / hr over 1, 2, 4, 8, 12, 18, or 24 hours. In the context of this disclosure, ppm is measured as mass / mass. In a special example, the glass composition contains enough fluoride for releasing about 4 to about 6 ppm of fluoride per hour over 1 hour.

[0033] In some examples of glass compositions according to this disclosure, the glass composition present in amounts less than 20 mol%, for example less than 15 mol, less than 10 mol, or less than 5 mol%, is CaO, MgO, and Na2O.

[0034] In an example of a glass composition according to this disclosure, the glass composition does not contain CuO, but contains less than 0.1 mol% of BaO and less than 0.1 mol% of P2O5. In particular, the glass composition does not contain CuO, BaO, or P2O5.

[0035] The glass composition according to this disclosure may contain about 5 mol% to about 50 mol% of one or more glass components selected from the group consisting of Li2O, Rb2O, K2O, Na2O, SrO, and ZnO, and the glass composition contains less than 0.1 mol% CaO and less than 0.1 mol% MgO.

[0036] The glass composition according to this disclosure may contain about 5 mol% to about 50 mol% of one or more glass components selected from the group consisting of Li2O, Rb2O, K2O, SrO, and ZnO, and the glass composition contains less than 0.1 mol% of CaO, less than 0.1 mol% of MgO, and less than 0.1 mol% of Na2O.

[0037] The glass composition according to this disclosure may contain about 50 mol% to about 80 mol% of B2O3, for example, about 50 mol% of B2O3.

[0038] The glass composition according to this disclosure may contain about 5 mol% to about 40 mol%, for example, about 20 mol% to about 40 mol%, of one or more glass components selected from the group consisting of Li2O, Rb2O, K2O, Na2O, SrO, CaO, MgO, and ZnO.

[0039] The glass compositions according to this disclosure may include B2O3, Li2O, and ZnO, and optionally Rb2O, Na2O, and / or a fluoride source. Specifically, the glass composition may contain about 5 mol% to about 25 mol% of Li2O, about 5 mol% to about 25 mol% of Rb2O, or about 5 mol% to about 25 mol% of Li2O, about 5 mol% to about 15 mol% of ZnO, and optionally about 5 mol% to about 15 mol% of Na2O, and the glass composition may contain about 50 mol% of B2O3, or about 70 mol% of B2O3.

[0040] The glass compositions according to this disclosure may include B2O3, ZnO, and optionally Rb2O and / or a fluoride source. In particular, the glass composition may contain about 5 mol% to about 30 mol% of ZnO. If present, RbO2 may be included in an amount of about 5 mol% to about 30 mol%. The glass composition may contain about 50 mol% of B2O3.

[0041] The glass compositions according to this disclosure may contain B2O3, SrO, and optionally ZnO and / or a fluoride source. In particular, the glass compositions contain about 5 mol% to about 30 mol% of SrO. If present, ZnO may be included in an amount of about 5 mol% to about 30 mol%. The glass compositions may contain about 50 mol% of B2O3.

[0042] As stated above, the Disclosure also provides glass compositions comprising about 5 mol% to about 10 mol% of fluorides, provided as CaF2, SnF2, NaF, KF, or any combination thereof; and about 90 mol% to about 95 mol% of combinations of B2O3, Na2O, MgO, and CaO, where boron, magnesium, Na and any combination of K, and Ca and any combination of Sn in the glass composition are present in elemental ratios of about 20:about 4:about 6:about 3, respectively.

[0043] One specific example of such a glass composition comprises about 50 mol% B2O3, about 15 mol% Na2O, about 20 mol% MgO, about 10 mol% CaO, and about 5 mol% CaF2. This composition may be referred to herein as composition "PBF1".

[0044] Another specific example of such a glass composition contains about 48 mol% B2O3, about 9 mol% Na2O, about 19 mol% MgO, about 14 mol% CaO, and about 10 mol% NaF. This composition may be referred to herein as composition "PBF1-Na".

[0045] Particle size distribution The glass composition according to this disclosure is a particulate material containing particles of about 1 to about 50 μm in size. At least some of the particles are sized to sit in or on dentinal tubules. Dentinal tubules have natural variations in diameter, mainly of about 0.5 to about 8 μm in size, for example, about 0.5 to about 5 μm in size. Accordingly, the glass composition according to this disclosure can be used for dentin desensitization, which can temporarily alleviate pain associated with sensitive teeth.

[0046] In some embodiments, at least 75% of the particles constituting the particulate material are smaller than 50 μm. In other embodiments, at least 85% or at least 95% of the particles are smaller than 50 μm. In some embodiments, at least 5% of the particles constituting the particulate material are smaller than 7 μm.

[0047] In certain embodiments, the particulate material is composed of multiple particles, at least 5% of which are smaller than 35 μm, at least 5% of which are smaller than 15 μm, and at least 5% of which are smaller than 7 μm.

[0048] In certain embodiments, the particulate material is composed of multiple particles, where at least 5% of the particles are approximately 15 μm to 35 μm in size, at least 5% of the particles are approximately 6 μm to 15 μm in size, and at least 5% of the particles are approximately 3 μm to 7 μm in size.

[0049] In some specific examples, the particulate material is composed of multiple particles with a particle size distribution of approximately 5 μm (Dx10), approximately 15 μm (Dx50), and approximately 30 μm (Dx90).

[0050] Decomposition The glass compositions according to this disclosure decompose under physiological conditions and lose at least 5% by mass within 24 hours upon exposure to buffered saline solution. In some examples, the glass compositions may lose at least 20% by mass, at least 40% by mass, at least 60% by mass, or at least 80% by mass within 24 hours upon exposure to buffered saline solution.

[0051] Dentin desensitizing composition The glass composition according to this disclosure can be formulated in a dentin desensitization composition containing an anhydrous, orally compatible carrier. The dentin desensitization composition according to this disclosure does not contain water, as the glass composition degrades when exposed to water.

[0052] In the context of this disclosure, “anhydrous” should be understood to mean that the dentin desensitization composition contains very little water, and that the glass composition remains capable of reducing dentin sensitivity over the expected lifespan of the product. The expected lifespan of the product refers to the longest expected time from when the dentin desensitization composition is produced until when the dentin desensitization composition is completely used up or discarded.

[0053] The orally compatible carrier used in the dentin desensitization composition may be an orally compatible viscous carrier such as a mouthwash, a carrier formulated to be mixed with additional ingredients to form a mouthwash, or a toothpaste, dental gel, prophylactic paste, dental varnish, adhesive, or carrier formulated to be mixed with additional ingredients to form a toothpaste. The orally compatible viscous carrier may have a viscosity of about 100 cP at 30°C to about 150,000 cp at 30°C.

[0054] As described above, the dentin desensitization composition may include the glass composition according to this disclosure, wherein the glass composition contains fluoride in an amount sufficient to contain about 100 ppm to about 5,000 ppm of fluoride in the desensitization composition.

[0055] An example of a dentin desensitizing composition according to this disclosure is a toothpaste comprising an abrasive, a detergent such as sodium lauryl sulfate, a fluoride source, an antimicrobial agent, a fragrance, a remineralizing agent, a sugar alcohol such as glycerol, sorbitol, or xylitol, another dentin desensitizing agent, a hydrophilic polymer such as polyethylene glycol, or any combination thereof. The glass composition may be about 0.5 to about 15% by mass of the toothpaste.

[0056] A specific example of a dentin desensitizing composition according to the present disclosure is a toothpaste comprising the glass composition according to the present disclosure, glycerin, silica, polyethylene glycol (such as PEG400), titanium dioxide, carbomer, and a sweetener (such as potassium acesulfame or sodium saccharin).

[0057] Another specific example of a dentin desensitizing composition according to the present disclosure is a toothpaste comprising the glass composition according to the present disclosure and α-carbomer, DL-limonene, glycerin, mint flavor, polyethylene glycol (e.g., PEG-8), silica, titanium dioxide, sodium lauryl sulfate, and a sweetener (e.g., acesulfame potassium or sodium saccharin).

[0058] Another example of a dentin desensitizing composition according to the present disclosure is a carrier comprising a glass composition according to the present disclosure, wherein the carrier is formulated to be mixed with additional components to form a toothpaste.

[0059] A further example of a dentin desensitizing composition according to this disclosure is a carrier formulated to be mixed with further components to form a mouthwash. Specific examples of carriers include the glass composition according to this disclosure and: anhydrous alcohol, cetylpyridinium chloride, chlorhexidine, essential oils, benzoic acid, poloxamer, sodium benzoate, flavoring agents, coloring agents, or any combination thereof. Additional components to be mixed with the carrier to form a mouthwash include water, peroxides, cetylpyridinium chloride, chlorhexidine, essential oils, alcohols, benzoic acid, poloxamer, sodium benzoate, flavoring agents, coloring agents, or any combination thereof. The carrier and additional components may be held in separate compartments and mixed together before the mixture is used as a mouthwash. The separate compartments may be in the form of a multi-chambered bottle, such as a branched bottle.

[0060] Another example of a dentin desensitizing composition according to this disclosure is a prophylactic paste (also called a “prophy paste”) comprising the glass composition according to this disclosure. Specific examples of the intended saprophylactic paste include the glass composition according to this disclosure and: pumice, glycerin, diatomaceous earth (preferably fine-grained), sodium silicate, methyl salicylate, monosodium phosphate, sodium carboxymethylcellulose, sweeteners (e.g., potassium acesulfame or sodium saccharin), flavorings, colorants, or any combination thereof.

[0061] method The glass compositions according to this disclosure can be synthesized by mixing appropriate molar amounts of starting reagents; filling a platinum crucible (Johnson Matthey, Noble Metals, Pennsylvania) with the precursor blend; placing the filled crucible at room temperature in a furnace (Carbolite, RHF1600); heating the furnace (e.g., at a rate of 25°C / min) to an initial residence temperature of 600°C; holding the temperature for 60 minutes; raising the temperature to a residence temperature of 1,100°C; holding the temperature for 60 minutes; and quenching the glass molten material between two stainless steel plates.

[0062] Please understand that the specific ramp speed, time, and temperature mentioned above can be modified as long as the glass continues to melt. By ramping at a rate of 10-20 degrees / minute and maintaining the residence temperature, at least some bubbles can be removed from the glass.

[0063] The resulting quenched glass is separately ground / milled in a planetary micromill (Pulverisette 7, Fritsch, Germany) and sieved through ASTM E-11 compliant sieves (Cole Palmer, USA) to obtain particles <25 μm. The glass can be stored under vacuum in glass scintillation vials.

[0064] The resulting glass composition contains oxides, but the starting reagents may include oxides, carbonates, or both. For example, the starting reagents may include boron oxide, rubidium carbonate, lithium carbonate, and calcium fluoride. Rubidium carbonate and lithium carbonate decompose in the furnace, releasing CO2 and generating their corresponding oxides.

[0065] Particle size is measured using a Malvern Mastersizer (MS) 3000 laser diffraction particle size analyzer. Glass powders are suspended separately in deionized water, and the clarity of the suspension is adjusted to 5-8%. The suspension is measured using both a blue laser (λ=470nm) and a red laser (λ=632.8nm), and five measurements (n=5) are performed.

[0066] Fluoride release is measured by placing 0.1 g of the glass composition into a 15 ml Falcon tube in 10 ml of TRIS-buffered saline (BioUltra, Sigma Aldrich, Canada). The solution is stirred at 120 rpm and maintained at 37°C for the desired release period, e.g., 1, 3, 6, 12, or 24 hours. After completion, the liquid portion is tilted and filtered into a new, clean 15 ml Falcon tube using a 0.22 μm filter (Sarstedt syringe filter, Canada), capped, and stored at 4°C until the amount of fluoride is quantified. The concentration of released fluoride is quantified using an Accμmet® AB250 pH / ion-selective electrode meter (Accumet®) equipped with a fluoride electrode combination. Standard solutions are prepared using fluoride analysis standards specifically for ion-selective electrodes (NaF, 0.1 MF, Sigma Aldrich, Canada), and calibration cures are collected before analysis. Liquid extracts derived from the extraction of each composition were prepared for ion analysis according to the electrode manufacturing instructions. Ion concentrations are reported as the average of n=3±SD.

[0067] In the context of this disclosure, the mass loss of the glass composition is in relation to a solid glass cylinder 6 mm in length and 4 mm in diameter. The glass cylinder is prepared by manufacturing molten glass as described above, placing the molten glass into a stainless steel mold (6 mm in length and 4 mm in diameter), setting it between two stainless steel plates, and quenching it. Excess glass on the cylinder is carefully etched with a speedy sharp instrument, and any remaining excess glass is removed using a grinding / polishing wheel with 240 grit sandpaper, with pressure applied to the mold / glass on the wheel. Glass cylinders with uneven edges, bubbles, and chips are excluded.

[0068] The mass loss of a given glass composition is measured using three cylinders. The length and diameter of each cylinder are measured and recorded three times (changing the measurement position), and the average value ± SD is recorded. The mass of each cylinder is measured separately (Sartorius Cubis, model MSU-224S 100DI, Cole Palmer). The three cylinders are placed in separate 50 mL Falcon tubes, each containing 20 mL of TRIS-buffered saline (BioUltra, Sigma Aldrich, Canada). The tubes are then placed in a shaking incubator (Thermos Scientific, MaxQ 4000) at 37°C and stirred at 120 rpm for 24 hours. After 24 hours, the cylinders are filtered from the solution, washed with cold distilled H2O, and dried overnight in an oven at 37°C. After drying, the length, diameter, and mass are measured.

[0069] The abrasion resistance of the composition is determined by measuring the gloss and surface roughness of the resin composite or enamel surface after brushing with the composition. ESPE Filtek Supreme Ultra Universal Restorative, shade A2B (3M, St. Paul, Minnesota, USA) is cured in a 12.7 mm diameter, 2 mm thick metal split mold. Mylar sheets are placed above and below the mold, and a glass plate is used to press the flat parts of the composite and squeeze out excess material. A broadband multi-wave LED light curing unit (Valo Grand, Ultradent Products, South Jordan, Utah, USA) is placed directly on the test specimen and cured for 20 seconds at the standard setting. Excess material is removed by hand, and then the specimen to be brushed is attached.

[0070] The sample should be stored in the dark at 37°C for at least 24 hours before use. The surface of the enamel sample is prepared by polishing with varying levels of grit to produce a flat and smooth surface. An initial flat surface (P800C, Klingspor, Haiger, Germany) is created using low-grit sandpaper, followed by polishing with a large amount of grit. The final polishing step is performed on a cloth pad with 3 μm and then 0.3 μm alumina oxide powder slurry (Buehler Ltd., Lake Bluff, Illinois, USA). Each polishing step is performed for approximately 1 minute under manual pressure.

[0071] The custom-made brushing machine (Ultradent, South Jordan, USA) simultaneously simulates brushing 10 samples of teeth. The toothbrushes (GMM brand 459PC, Sunstar, Guelph, Ontario, Canada) are equipped with a constant load of 176g during brushing. The toothbrushes are replaced after 10,000 brushing cycles. During brushing, the samples are covered with a minimum of 3mm of toothpaste slurry in a 5:8 weight ratio with distilled water. Every 2,500 brushing cycles, the samples are rotated to a different position (to ensure that the same toothpaste is used each time the sample is moved). 20,000 brushing cycles represent approximately two years of brush polishing. The repetition and position of the toothpaste within the machine are randomly assigned by a random number generator (for each substrate material), while manual assurance is given that there are at least two repetitions of the same toothpaste during a single run to ensure toothbrush rotation.

[0072] A gloss meter (Novo-Curve G, Rhopoint Instruments, Hastings, UK) is used to measure the gloss of composite materials and enamel surfaces. Gloss is measured at three random points, and the average value of the surface is calculated. Gloss meter calibration is verified daily using traceable calibration tiles with high and low reflectivity. Gloss is measured at 0, 5,000, 10,000, 15,000, and 20,000 brush cycles, and a new toothpaste slurry is used after each gloss measurement.

[0073] The average surface roughness was also measured before brushing and after 20,000 brushing cycles. An atomic force microscope (nGauge, ICSPI Corporation, Rev. 1.0, Waterroo, Ontario, Canada) was used to measure the average roughness at three different locations and form the surface average. A 25 × 25 μm area was scanned at a speed of 1200 μs / pixel. Analysis was performed using Gwyddion software (http: / / gwyddion.net). [Examples]

[0074] All glass compositions shown in Table 1 were synthesized by weighing quantitative amounts of analytical-grade reagents (boron oxide, rubidium carbonate, lithium carbonate, and calcium fluoride) (Sigma Aldrich, Canada). To ensure homogeneity, each formulation was mixed for 60 minutes. Each precursor blend was placed and packed into a 50 mL platinum crucible (Johnson Matthery, Noble Metals, Pennsylvania). The packed crucible was then placed in a furnace (Carbolite, RHF 1600) at room temperature. The furnace was heated to an initial habituation temperature of 600°C (25°C / min) and held for 60 minutes. The temperature was then increased to a final habituation temperature of 1,100°C (20°C / min) and held for 60 minutes. Upon removal, each glass molten material was quenched between two stainless steel plates. The resulting quenched glass was separately ground / milled in a planetary micromill (Pulverisette 7, Fritsch, Germany) and sieved through an ASTM E-11 compliant sieve (Cole Palmer, USA) to obtain particles <25 μm.

[0075] [Table 1]

[0076] Table 2 shows the particle size distribution of the exemplary glass shown in Table 1.

[0077] [Table 2]

[0078] Here, "Dx(#)" refers to the percentage of particles smaller than the noted value. For example, BCF100 has a Dx(10) of 5.16 microns, which means that 10% of the particles are smaller than 5.16 microns.

[0079] The exemplary glass particles shown in Table 1 were evaluated for fluoride release in buffered saline solution over 12 and 24 hours using the method described above. The ppm values ​​of the released fluoride are shown in Table 3.

[0080] [Table 3]

[0081] BCF201 was incorporated into two toothpastes, and the abrasive effect of the glass particles was tested and compared to that of Sensodyne® Whitening Restorative and Protect® toothpaste ("Sensodyne") and Colgate® Optic White® toothpaste ("Colgate Optic"). Exemplary glass was formulated in (a) Colgate® Enamel Health Sensitivity Relief® (Colgate-Palmolyb, Toronto, ON, Canada) ("Colgate EN") or (b) Gel7HT (Germiphene, Brantford, ON, Canada) ("Gel"), both neutral pH fluoride gel toothpastes that do not contain any abrasive materials.

[0082] The results of the polishing tests are shown in the following tables and Figures 1-10. Table 4 shows the glossiness of the resin composite surface after a different number of brushing cycles using different toothpastes. Table 5 shows the glossiness of the resin composite after a different number of brushing cycles using different toothpastes. Table 6 shows the surface roughness of the resin composite after 20,000 brushing cycles using different toothpastes. Table 7 shows the surface roughness of the enamel after 20,000 brushing cycles using different toothpastes.

[0083] [Table 4]

[0084] [Table 5]

[0085] [Table 6]

[0086] [Table 7]

[0087] Further exemplary glass compositions described herein are shown in Table 8, along with non-exemplary glass compositions showing the molar percentages of different components.

[0088] [Table 8-1]

[0089] [Table 8-2]

[0090] The exemplary glass compositions and additional compositions shown in Table 8 were selected based on the design of the mixture (Design Expert 8.0.4, Stat-Ease Inc.), and the effects of various ranges of components on the glass composition were evaluated.

[0091] The glass compositions were synthesized as described above. Briefly, sufficient amounts of analytical-grade reagent (Sigma Aldrich, Canada) necessary to form each of the above compositions were weighed out. To ensure homogeneity, each formulation was mixed for 60 minutes. Each precursor blend was placed and packed into a 50 mL platinum crucible (Johnson Matthery, Noble Metals, Pennsylvania). The packed crucible was then placed in a furnace (Carbolite, RHF 1600) at room temperature. The furnace was heated to an initial habitability temperature of 600°C (25°C / min) and held for 60 minutes. The temperature was then increased to a final habitability temperature of 1,100°C (20°C / min) and held for 60 minutes. Upon removal, each glass molten material was quenched between two stainless steel plates.

[0092] The following compositions are specific examples of compositions in which glass was formed under the quenching conditions described above, and such conditions represent one option for standard quenching conditions suitable for a manufacturing scale process.

[0093] [Table 9]

[0094] The quenched glass obtained for the exemplary compositions listed in Table 9 had the following bulk properties:

[0095] [Table 10]

[0096] The quenched glass obtained for the exemplary compositions listed in Table 9 was separately ground / milled in a planetary micromill (Pulverisette 7, Fritsch, Germany) and sieved through ASTM E-11 compliant sieves (Cole Palmer, USA) to obtain particles of <25 μm.

[0097] Table 11 shows the particle size distribution of the exemplary glasses listed in Table 9. BCF315 and BCF326 decomposed too rapidly in deionized water, making it impossible to obtain accurate particle size measurements.

[0098] [Table 11]

[0099] The exemplary glass particles listed in Table 9 were evaluated for mass loss and fluoride release in buffered saline solution at 1, 4, and 24 hours. Samples were prepared, weighed, and recorded in 15 mL triangular test tubes (n=3). 0.1 gram of each glass powder (<25 microns) was weighed separately and placed in 10 mL of TRIS buffered saline (BioUltra, Sigma Aldrich, Canada) in a weighed 15 mL Falcon tube. After sealing the tube with Parafilm, it was placed in a shaking incubator at 37°C and stirred at 120 rpm for four separate time points: 5 minutes, 30 minutes, 1 hour, 3 hours, 24 hours, and 48 hours. After the specified time elapsed, the tube was removed from the incubator and the solution was immediately centrifuged at 3.0 RCF / 4.4 RPM for 15 minutes (Eppendorf, Centrifuge 5702). The supernatant was decanted into a fresh 15 mL Falcon tube. Furthermore, the powder samples incubated for 48 hours were resuspended in 10 mL of fresh TRIS-buffered saline by vortex mixing and incubated for a further 8 hours (for a total incubation period of 56 hours). The re-incubated powders were processed in the same manner as the other samples. The pellets were dried in their respective Falcon tubes in a 50°C oven.

[0100] The release of fluoride ions was measured using an Accμmet AB250 pH / ion selectivity meter equipped with a fluoride electrode (Fisher Scientific). To calibrate the probe, six standard solutions were prepared using fluoride analytical standards for ion selectivity electrodes (NaF, 0.1F, Sigma Aldrich, Canada). Standards with fluoride concentrations of 1000 ppm, 100 ppm, 10 ppm, 1 ppm, 0.1 ppm, and 0.01 ppm were synthesized using TRIS-buffered saline (BioUltra, Sigma Aldrich, Canada) as the solvent. Before calibration, 4.5 mL of TISAB concentrate was added to each standard (according to the manufacturer's instructions). After the probe was calibrated, the gradient of the standard was checked to ensure it was within the range specified in the instructions for use. 1.0 mL of TISAB concentrate was added to the decant supernatant, and the fluoride concentration was then measured using the calibrated probe. Ion concentrations are reported as mean ± SD.

[0101] Table 12 shows the mass loss and ppm values ​​of the released fluoride. BCF314 completely decomposed in buffered saline solution before the 1-hour mark, and no further fluoride sources were present.

[0102] [Table 12]

[0103] The compositions listed in Table 8 reflect the design space. The results of the tested compositions provided the following equation, which may allow for relative comparisons of different compositions and / or may be useful in identifying trends associated with different components of a composition. Experimental and modeling errors prevent absolute prediction of glass properties, but this equation can be used to guide and improve glass composition design. Used together, these models will help suggest which factors may be traded off in the tuning of multi-component compositions within the tested composition space. In the following equation, the values ​​of the listed components are given as percentages (not decimals). For example, 50 mol% B2O3 is "50" (not "0.5").

[0104] Glass is generally expected to form under the tested quench conditions if the following equation is 1.60 or less: (2.01 × e y (+0.99) / (1+e y ) Here, y=-0.086622×[B2O3]+0.14169×[Li2O]-0.565849×[ZnO]+0.192175×[Na2O]-0.461537×[CaF2]+0.036 636×[KF]+0.00365×[NaF]+0.191201×[SnF2]+0.192612×[RbO2]+0.199999×[SrO]+0.01393×[B2O3]×[ZnO] +0.012239×[B2O3]×[CaF2]-0.012412×[Li2O]×[CaF2]-0.013904×[Li2O]×[RbO2]-0.010857×[ZnO]×[CaF2 ]-0.013296×[ZnO]×[RbO2]-0.010699×[ZnO]×[SrO]+0.010128×[CaF2]×[KF]-0.012103×[CaF2]×[SrO].

[0105] The density of glass can generally be predicted using the following formula: ρ = 0.018783×[B2O3] + 0.026444×[Li2O] + 0.046191×[ZnO] + 0.033814×[Na2O] + 0.039196×[CaF2] + 0.026997×[KF] + 0.029458×[NaF] + 0.049441×[SnF2] + 0.047057×[R b O2] + 0.054984×[SrO] About 1.3 g / cm 3 to about 2.2 g / cm 3 The glass density up to can be particularly beneficial in non-aqueous oral care formulations. Glycerol and silica are the main liquid and solid components of the non-aqueous toothpaste, having densities of 1.3 and 2.2 g / cm 3 respectively.

[0106] The glass transition temperature (T g ) can generally be predicted using the following equation: T g = 3.49398×[B2O3] + 3.66342×[Li2O] + 6.38755×[ZnO] + 6.23689×[Na2O] + 6.43079×[CaF2] + 3.31695×[KF] + 5.04074×[NaF] + 9.88761×[SnF2] + 3.29777×[RbO2] + 10.51264×[SrO] It should be understood that phase-separated glasses can exhibit multiple glass transitions, and the magnitudes thereof do not necessarily represent the volume distribution of the phases. The above equation predicts the onset of the glass transition, but when phase separation occurs, the predicted onset may not be the main glass transition of the composition. Therefore, the predicted glass transition temperature may be significantly different from the measured main glass transition temperature.

[0107] The equation for the mass loss rate after 1 hour under test conditions is as follows: (100×e y ) / (1 + e y ) Here, y = 0.088098 × [B2O3] + 0.062481 × [Li2O] - 0.262486 × [ZnO] + 0.05542 × [Na2O] - 0.165517 × [CaF2] + 0.089171 × [KF] + 0.075875 × [NaF] + 0.10439 × [SnF2] + 0.109897 × [RbO2] - 0.089987 × [SrO] The above equation is highly predictive in identifying glass compositions that will completely dissolve within one hour under the tested conditions and may be useful in identifying other glasses that degrade within this timeframe. Furthermore, although this equation does not provide accurate mass loss estimates for slower-degrading compositions, it may be useful in predicting the relative changes in decomposition expected to occur with changes in composition. Such relative changes can be used as a guide for glass composition design.

[0108] The formula for the release of fluoride (ppm) after 1 hour under test conditions is as follows: (2750×e y ) / (1+e y ) Here, y = -0.05785 × [B2O3] - 0.15837 × [Li2O] - 0.170872 × [ZnO] - 0.184773 × [Na2O] + 0.05638 × [CaF2] + 0.101381 × [KF] + 0.053886 × [NaF] - 0.307462 × [SnF2] - 0.183034 × [RbO2] - 0.184126 × [SrO] While the above formula does not provide an accurate estimate of the amount of fluoride released for all glass compositions, this model is still useful for predicting the relative changes in fluoride release that are expected to occur with changes in composition.

[0109] PBF1 was synthesized from 11.60 g of B2O3, 5.30 g of Na2CO3, 2.69 g of MgO, 3.33 g of CaCO3, and 0.7 g of CaF2 (Sigma Aldrich, Canada). To ensure homogeneity, the starting materials were mixed for 60 minutes. The blend was set aside and packed into a 50 mL platinum crucible (Johnson Matthey, Noble Metals, Pennsylvania). The packed crucible was then placed in a furnace (Carbolite, RHF 1600) at room temperature. The furnace was heated to an initial habitability temperature of 600 °C (25 °C / min) and held for 60 minutes. The temperature was then increased to a final habitability temperature of 1,200 °C (20 °C / min) and held for 60 minutes. Upon removal, the glass molten material was quenched between two stainless steel plates. The resulting quenched glass was separately ground / milled in a planetary micromill (Pulverisette 7, Fritsch, Germany) and sieved through an ASTM E-11 compliant sieve (Cole Palmer, USA) to obtain particles <25 μm.

[0110] Comparative glass compositions (referred to as Comparative Examples (CE) 1 and 2) were similarly synthesized using 5.80 g of B2O3, 23.66 g of P2O5, 5.30 g of Na2CO3, 1.34 g of MgO, 6.67 g of CaCO3, and 0.70 g of CaF2. CE1 consists of approximately 25 mol% B2O3, approximately 25 mol% P2O5, approximately 15 mol% Na2O, approximately 10 mol% MgO, approximately 20 mol% CaO, and approximately It contained 5 mol% CaF2; and it was synthesized using 5.80 g B2O3, 23.66 g P2O5, 7.07 g Na2CO3, 1.34 g MgO, 5.00 g CaCO3, and 0.70 g CaF2, and CE2 contained approximately 25 mol% B2O3, approximately 25 mol% P2O5, approximately 20 mol% Na2O, approximately 10 mol% MgO, approximately 15 mol% CaO, and approximately 5 mol% CaF2.

[0111] The density of glass powder is 1 cm 3 Measurements were taken using an AccuPyc 1340 helium pycnometer (MicroMerix, USA) equipped with an insert. Before use, the volume was 0.718512 cm³.3 The pycnometer was calibrated using the standard. For glass analysis, approximately 0.5–0.7 grams of glass powder were packed into the insert. Three samples were measured from each glass, and each measurement was the average of 10 readings.

[0112] The density of PBF1 is 2.5951 ± 0.0072 g / cm³. 3 The following measurements were taken: The density of CE1 is 2.7079 ± 0.0021 g / cm³. 3 The following measurements were taken: CE2 density was 2.6749 ± 0.0013 g / cm³. 3 This was measured.

[0113] Fluoride release and mass loss were measured for PBF1, CE1, and CE2. Samples were prepared, weighed, and recorded in 15 mL triangular test tubes (n=3). 0.1 gram of each glass powder (<25 microns) was weighed separately and placed in 10 mL of TRIS-buffered saline (BioUltra, Sigma Aldrich, Canada) in weighed 15 mL Falcon tubes. After sealing the tubes with Parafilm, they were placed in a shaking incubator at 37°C and stirred at 120 rpm for four separate time points: 5 minutes, 30 minutes, 1 hour, 3 hours, 24 hours, and 48 hours. After the specified time periods, the tubes were removed from the incubator and the solutions were immediately centrifuged at 3.0 RCF / 4.4 RPM for 15 minutes (Eppendorf, Centrifuge 5702). The supernatant was decanted into fresh 15 mL Falcon tubes. Furthermore, the powder samples incubated for 48 hours were resuspended in 10 mL of fresh TRIS-buffered saline by vortex mixing and incubated for a further 8 hours (for a total incubation period of 56 hours). The re-incubated powders were processed in the same manner as the other samples. The pellets were dried in their respective Falcon tubes in a 50°C oven.

[0114] The release of fluoride ions was measured using an Accμmet AB250 pH / ion selectivity meter equipped with a fluoride electrode (Fisher Scientific). To calibrate the probe, six standard solutions were prepared using fluoride analytical standards for ion selectivity electrodes (NaF, 0.1F, Sigma Aldrich, Canada). The sodium fluoride concentrations of the standards were synthesized using TRIS-buffered saline (BioUltra, Sigma Aldrich, Canada) as the solvent to 1000 ppm, 100 ppm, 10 ppm, 1 ppm, 0.01 ppm, and 0.001 ppm, respectively. Before calibration, 4.5 mL of TISAB concentrate was added to each standard (according to the manufacturer's instructions). After the probe was calibrated, the standard gradient was checked to ensure it was within the range specified in the instructions for use. 1.0 mL of TISAB concentrate was added to the decant supernatant, and the fluoride concentration was then measured using the calibrated probe. Ion concentrations are reported as mean ± SD.

[0115] The amount of fluoride ions released by PBF1 was measured as 89±2 ppm at 5 minutes, 94±3 ppm at 30 minutes, 105±5 ppm at 1 hour, and 94±7 ppm at 3 hours. Fluoride ions released by CE1 or CE2 could not be measured.

[0116] Mass loss was calculated by comparing the mass of the dried sample after exposure to TRIS-buffered saline with the initial mass of the sample. The mass loss of PBF1 was 42.0±2.1% after 5 minutes, 47.3±2.7% after 30 minutes, 51.5±4.3% after 1 hour, 41.7±5.7% after 3 hours, 70.1±6.8% after 24 hours, and 100% after 48 hours.

[0117] The particle sizes of seven different PBF1 samples were measured using a Malvern Mastersizer 3000 model laser diffraction particle size analyzer. Glass particles were suspended separately in distilled water to obtain an obscurity of 2–5%. Prior to analysis, the glass powder was stored in a vacuum desiccator, removed for analysis, and repeated 3 × 5 times for approximately 20 seconds each time. The suspensions were measured using both blue (λ=470nm) and red (λ=632.8nm) lasers (n=5).

[0118] [Table 13]

[0119] Apatite formation in the simulated body fluid was confirmed in PBF1, but not in CE1 or CE2. The simulated body fluid was synthesized according to the methods and instructions published by Kokubo and Takadama (Kokubo, T. and Takadama, H. Biomaterials (2006) 27:15, pp 2907-2915).

[0120] SBF was prepared in 1L batches in 1000mL Nalgene bottles (FEP bottles). The prepared SBF was stored at room temperature for 24 hours immediately after synthesis to ensure stability before experimental use. The SBF was stored in tightly sealed Nalgene bottles and kept at 6°C if not immediately needed (up to 30 days for experimental use).

[0121] According to the TCO4 method (published in Mason, ALB, Kim, TB, Valliant, E et al. J Mater Sci: Mater Med (2015) 26:115), 0.75 g of glass powder from each glass composition (n=3) was immersed in 50 mL of SBF in a polyethylene container, as synthesized above. The container was then placed in an incubator orbital shaker at 37°C and stirred at 120 rpm for three time points: 30 minutes, 3 hours, and 12 hours. After the elapsed time, each sample was vacuum filtered through Whatman 42 or 5 grade filter paper (particle retention rate 2.5 μm) to recover the solid material from the solution. The solid was immediately washed with distilled water and acetone to stop further reaction.

[0122] The filtered samples were dried in a vacuum desiccator for further analysis. Imaging of each sample was performed using a Hitachi S-4700 FEG (Hitachi, Chula Vista, Ca) scanning electron microscope operated at 3KV and 15mA at magnifications of 1000× and 10000×. The samples were mounted on stubs using double-sided carbon tape and coated with gold-palladium sputtering for 70 seconds (Leica EM ACE200, Wetzlar, Germany). Scanning electron microscope images of PBF1 at 30 minutes, 3 hours, and 12 hours are shown in Figures 11-14.

[0123] PBF1 also developed an application protocol to evaluate dentinal tubular occlusion by statistical analysis of SEM images graded by two evaluators according to a category occlusion scale. Sections of human dentin (approximately 1-1.5 mm thick) were prepared from the crowns of caries-free, unstorable molars perpendicular to the long axis of the root using a diamond disc saw. Each section was etched with 10% citrate for 2 minutes, followed by rinsing with water for 60 seconds, ultrasonic treatment for 2 minutes, and rinsing with water for another 60 seconds. Each section was placed in a 25 mm diameter mold and covered with acrylic resin to a depth of 3 mm. Once the resin had hardened, the dentin surface was sequentially polished with 800 and 2500 grit sandpaper for a mirror finish. After rinsing with deionized water, the surface was etched, ultrasonically treated, and rinsed again. The integrity, tubular density, and patency of the samples were examined again under a light microscope and then by SEM.

[0124] One dentin sample was assigned to each treatment group. The dentin sample was treated with (i) an exemplary unformed mixture of glass particles, (ii) a test toothpaste containing an exemplary mixture of glass particles, or (iii) a control toothpaste without additional glass particles. The unformed mixture was applied for 10 seconds using fingers with non-powdered nitrile gloves. The test toothpaste and control toothpaste were applied to the sample for 10 seconds using an electric toothbrush. After the toothpaste was left for 30 seconds, it was rinsed until all visible paste was removed. This was repeated for a total of four applications of toothpaste.

[0125] Dentin samples were dried in an oven at 37°C for 1 hour, coated with gold, and visualized using a Phenom ProX scanning electron microscope. Five 3000x images were taken from different parts of each sample. In these parts, the tubules were perpendicular to the surface. Each 3000x micrograph was examined by two single-blind evaluators for the prolongation of dentinal tubular obstruction based on a 5-point category scale. The malignancy classification was defined as follows: 1. Occlusion (100% occlusion) 2. Almost completely blocked (75% blocked) 3. Equivalent (50% occlusion) 4. Almost non-occlusive (25% occlusion) 5. Non-occlusion (0% occlusion)

[0126] The average score for each image was calculated from the scores of two evaluators. Standard deviation was calculated, but formal statistical comparisons could not be performed because only one dentin sample was used per treatment group.

[0127] As outlined in Table 14, seven different treatment groups were tested.

[0128] [Table 14]

[0129] As described above, each sample treatment group was tested with dentin samples, and five SEM images were taken of each sample at ×3000. Each micrograph was classified and evaluated by two evaluators. The group mean score and standard deviation were calculated by combining the average score of each micrograph with the five micrographs per sample (see Table 15).

[0130] [Table 15]

[0131] The mean baseline score of 4.90 in treatment group 1 indicates that virtually all dentinal tubules were unoccluded. The mean score of 1.50 for formless PBF1 directly rubbed into the dentin sample indicates nearly complete tubular occlusion.

[0132] Treatment groups 5, 6, and 7 (control groups lacking PBF1 or other glass compositions as described herein) had mean occlusion scores of 3.2–3.6. Treatment groups 3 and 4 (commercial toothpaste containing 5% or 15% PBF1 w / w) showed lower mean occlusion scores and a higher degree of tubular obstruction. The degree of obstruction with the commercial toothpaste Sensodyne® Complete Protection increased from approximately 30% obstruction (score 3.6) to approximately 50% obstruction (score 2.5) when 15% w / w PBF1 was added.

[0133] PBF1 was further evaluated for dentinal tubular occlusion using 5% w / w PBF1 sodium lauryl sulfate (SLS) paste. In this evaluation, PBF1 toothpaste and control toothpaste were applied to three different dentin samples from each treatment group. Each sample was brushed once with the treated toothpaste for 2 minutes. Specifically, each dentin sample was brushed with 0.25 g of treated toothpaste for 120 seconds, followed by rinsing with DI water for 30 seconds. The 5% PBF1-SLS paste yielded a mean occlusion score of 2.7 ± 0.84. The SLS paste without PBF1 yielded a mean occlusion score of 3.80 ± 1.03. In a controlled study using Sensodyne® Repair & Protect, the mean occlusion score was 3.90 ± 0.66.

[0134] PBF1-Na was prepared according to the protocol described above. Briefly, the glass was synthesized from 11.05 g of B2O3, 3.36 g of Na2CO3, 2.56 g of MgO, 4.77 g of CaCO3, and 1.33 g of NaF (Sigma Aldrich, Canada). To ensure homogeneity, the starting materials were mixed for 60 minutes. The blend was set aside and packed into a 50 mL platinum crucible (Johnson Matthey, Noble Metals, Pennsylvania). The packed crucible was then placed in a furnace (Carbolite, RHF 1400) at room temperature. The furnace was heated to an initial habitability temperature of 600 °C (25 °C / min) and held for 60 minutes. The temperature was then increased to a final habitability temperature of 1,200 °C (20 °C / min) and held for 60 minutes. Upon removal, the molten glass was quenched between two stainless steel plates. The resulting quenched glass was separately ground / milled in a planetary micromill (Pulverisette 6, Fritsch, Germany) and sieved through an ASTM E-11 compliant sieve (Cole Palmer, USA) to obtain particles <25 μm.

[0135] The particle sizes of 10 different samples of PBF1-Na were measured as described above.

[0136] [Table 16]

[0137] As mentioned above, the density, % crystallinity, and glass transition temperature of the 10 types of samples were also measured.

[0138] [Table 17]

[0139] For 10 different samples, the mass loss and fluoride release after 24 hours were also measured as described above.

[0140] [Table 18]

[0141] The above description includes numerous details for the purpose of explanation and to fully understand the examples. However, it will be apparent to those skilled in the art that these specific details are unnecessary. Therefore, what is described is merely illustrative of the application of the described examples, and numerous modifications and variations are possible in light of the above teachings.

[0142] Since the above description provides examples, it will be understood that modifications and variations can be made for specific embodiments by those skilled in the art. Accordingly, the claims should not be limited by the specific embodiments described herein, but should be interpreted in a manner consistent with the specification as a whole.

Claims

[Claim 1] B ２ O ３ ; Li ２ O, Rb ２ O, K ２ O, Na ２ One or more glass components selected from the group consisting of O, SrO, CaO, MgO, and ZnO; 0 mol% CuO; BaO less than 0.1 mol%; and P less than 0.1 mol% ２ O ５ A glass composition containing, The glass composition contains less than 30 mol% of Rb ２ O and The glass composition is a system of at least four components. When the glass composition is exposed to a buffered saline solution, it loses at least 5% by mass within 24 hours. The glass composition is a particulate material containing particles with a size of approximately 1 to approximately 50 μm.

Images