Customized zirconia gel articles, zirconia dental prostheses, and methods of production

Abstract

The present invention relates to a tailored zirconia gel article having a dental restoration shape, the tailored zirconia gel article comprising a transition region comprising a transition gel, the transition region having a color gradient, the material composition of the transition gel comprises crystalline zirconia particles, a crystalline phase stabilizer component, a cured organic component, an optional photoinitiator, a liquid and a coloring component, and the crystalline phase stabilizer component is contained in the crystalline zirconia particles. And an optional colouring component may be included in the crystalline zirconia particles or present as a separate component in the gel. Furthermore, the invention relates to a method for producing such tailored zirconia gel articles.

Description

Technical Field

[0001] This invention relates to a custom zirconia gel product having the shape of a dental prosthesis and a dental prosthesis, particularly a monolithic zirconia ceramic dental prosthesis obtained therefrom, and a method for producing a zirconia ceramic dental prosthesis.

[0002] Zirconia ceramic dental restorations offer high aesthetic appeal and sufficient physical and mechanical properties. They can be manufactured without powder pressing or milling steps. Zirconia dental restorations can also be characterized by customizable color and translucency variations, allowing them to mimic the aesthetics of natural teeth. Background Technology

[0003] The literature also describes various methods for producing dental milled blanks and for producing dental restorations from milled blanks or through other processes.

[0004] US 9,039,947 B2 (Jahns et al.) describes a method for manufacturing a layered dental appliance, the method comprising: providing a mold comprising a negative shape of the form of a layered dental appliance; placing a slurry in the mold to form a first layer of the layered dental appliance, the slurry comprising: (i) at least one of glass powder and glass-ceramic powder, present in an amount of 60% to 85% by weight, (ii) a liquid, and (iii) an inorganic binder precursor; providing a solid structure comprising a positive shape of a second layer of the layered dental appliance, wherein the solid structure comprises a compression mold; pressing the solid structure into the slurry in the mold; and removing the solid structure from the slurry to form a cavity in the slurry comprising a negative shape of the second layer.

[0005] US 10,028,809 B2 (Jahns et al.) describes a porous dental milling block comprising at least two geometrically defined material segments A and B, wherein material segment A contains a tetragonal zirconia phase in weight percent (AT) and a cubic zirconia phase in weight percent (AC), and material segment B contains a tetragonal zirconia phase in weight percent (BT) and a cubic zirconia phase in weight percent (BC), wherein (weight percent of tetragonal phase AT) / (weight percent of cubic phase AC) > 1 and (weight percent of tetragonal phase BT) / (weight percent of cubic phase BC) < 1, and the materials of material segments A and B exhibit N2 adsorption and / or desorption behavior according to isotherm IV classified by IUPAC.

[0006] US 2022 / 0380260 A1 (Shah et al.) relates to an additive manufacturing method for producing ceramic articles, the method comprising: a) obtaining a photopolymerizable sol comprising a plurality of ceramic particles distributed in the photopolymerizable sol, wherein the ceramic particles have an average particle size diameter of 1 nanometer (nm) to 100 nm; b) selectively polymerizing the photopolymerizable sol to form a gel article by using photochemical radiation and continuously moving a building substrate through the photopolymerizable sol; c) extracting a solvent from the gel article to form an aerogel article or a dry gel article; d) heat-treating the aerogel article or the dry gel article to form a porous ceramic article; e) sintering the porous ceramic article to form a sintered ceramic article; wherein the sintered ceramic article exhibits a density of 98% or higher relative to the theoretical density of the ceramic material, and wherein the sintered ceramic article exhibits an opacity of 80% or lower.

[0007] US 10,759,707 B2 (Mayr et al.) describes a method for producing ceramic articles, the method comprising: providing a printing sol, wherein the printing sol comprises a solvent, nanoscale particles, a radiation-curable monomer, and a photoinitiator, and wherein the printing sol has a curability of less than 500 mPa at 23°C. The viscosity of s; processing the printing sol as a building material in an additive manufacturing process to obtain a three-dimensional article in a gel state having a volume A; converting the three-dimensional article in the gel state into a three-dimensional article in a dry state, i.e., aerogel or dry gel; and applying a heat treatment step to obtain a sintered ceramic article having a volume F; wherein the volume A of the three-dimensional article in the gel state is more than 500% of the volume F of the ceramic article in its sintered state.

[0008] US 10,532,008 B2 (Balasubramanian et al.) describes a colored zirconia ceramic material for use in dental applications, comprising: a yttrium-stabilized zirconia material containing 4.7 mol% to 5.1 mol% yttrium oxide; a colorant comprising at least one metal selected from: a) Tb as Tb₄O₇ in an amount of 0.005 wt% to 0.025 wt%; b) Cr as Cr₂O₃ in an amount of 0.0002 wt% to 0.0009 wt%; c) Er as Er₂O₃ in an amount of 0.022 wt% to 0.3 wt%; and Co as Co₃O₄ in an amount of 0 wt% to 0.0001 wt%; and optionally alumina in an amount of 0 wt% to 0.25 wt%, wherein the colored zirconia ceramic exhibits a flexural strength of at least 800 MPa upon complete sintering. Summary of the Invention

[0009] However, there is still a need for highly aesthetic dental restorations that can be customized or personalized based on the dental condition in a patient's mouth during the early manufacturing stages.

[0010] The dental restoration should be strong enough and highly translucent in a specific zone.

[0011] Ideally, the dental restoration should be provided in a "ready-to-use" form, meaning that no additional glazing step is required.

[0012] If possible, powder pressing and / or milling steps should also be avoided.

[0013] One or more of these objectives can be achieved by the invention described herein.

[0014] This invention relates to a custom zirconia gel product, a dental restoration, and a method for manufacturing the same, as described in the claims and specification.

[0015] In particular, the present invention relates to a custom zirconia gel article having the shape of a dental prosthesis, the custom zirconia gel article including a transition region comprising a transition gel having a color gradient, the material composition of the transition gel comprising crystalline zirconia particles, a phase stabilizer component, a cured organic component, an optional photoinitiator, a liquid, and a coloring component, wherein the phase stabilizer component is contained in the crystalline zirconia particles, and the coloring component may be contained in the crystalline zirconia particles or exist as a separate component in the gel.

[0016] Furthermore, the present invention relates to a method for producing custom zirconia gel articles as described herein and in the claims, the method comprising the steps of: placing a curable sol S1 in an amount of A1 in a mold having a non-planar inner bottom surface; placing a curable sol S2 in an amount of A2 in contact with the curable sol S1; optionally, placing a curable sol S2 in an amount of A... N Curable sol S N Place them in contact with sol S1 and / or sol S2, where N = 1, 2, 3, 4...; perform the curing step, sol S1, sol S2 and optional sol S... N Each sol comprises crystalline zirconia particles, a crystal phase stabilizer component, a curable organic component, a photoinitiator, an optional coloring component, and a liquid. The crystal phase stabilizer component is contained within the crystalline zirconia particles, and the optional coloring component may be contained within the crystalline zirconia particles or exist as a separate component in the sol. At least sol S2 contains the coloring component. The viscosity of each sol is 50 mPa at 23°C. s to 3,000 mPa Within the range of s; and wherein sol S1, sol S2 and optional sol S NThey differ from each other individually or in combination in the following properties: the content of coloring components, the content of phase-stabilizing components, and the content of crystalline zirconia particles.

[0017] The present invention also relates to a zirconia dental restoration that can be obtained from a custom-made zirconia gel product. Attached Figure Description

[0018] Figure 1 A photograph of a dental restoration according to Embodiment 1 of the present invention is shown.

[0019] Figure 2 A schematic diagram of a method for producing the dental restoration of Example 1 is shown.

[0020] Figure 3 A photograph of a dental restoration according to Embodiment 2 of the present invention is shown.

[0021] Figure 4 A schematic diagram of a method for producing the dental restoration of Example 2 is shown.

[0022] Figure 5 A photograph of a dental restoration according to Embodiment 3 of the present invention is shown.

[0023] Figure 6 A schematic diagram of a method for producing the dental restoration of Example 3 is shown.

[0024] Figure 7 A photograph of the dental restoration according to Comparative Example 1 is shown.

[0025] Figure 8 A photograph of the dental restoration according to Comparative Example 2 is shown. Detailed Implementation

[0026] Unless otherwise defined, the following terms shall have the given meaning for the purposes of this specification: "Cureable, curable, or polymerizable component" is any component that can be cured or solidified by radiation-induced polymerization in the presence of a photoinitiator or by heat treatment. A cureable component may contain only one, two, three, or more polymerizable groups. Typical examples of polymerizable groups include unsaturated carbon groups, such as vinyl groups, which are particularly present in (meth)acrylate groups.

[0027] As used herein, “(meth)acryloyl” is an abbreviation for “acryloyl” and / or “methacryloyl”. For example, “(meth)acryloyloxy” is an abbreviation for an acryloyloxy group (i.e., CH2=CH-C(O)-O-) and / or a methacryloyloxy group (i.e., CH2=C(CH3)-C(O)-O-).

[0028] As used herein, the terms "hardening" and "curing" are used interchangeably and refer to polymerization and / or crosslinking reactions involving one or more materials contained in the composition, including, for example, photopolymerization and chemical polymerization techniques (e.g., ionic or chemical reactions that form free radicals that effectively polymerize olefinic unsaturated compounds).

[0029] "Dental articles" refers to articles intended for use in the dental or orthodontic field, particularly as or for the manufacture of dental restorations. Dental articles typically have two distinct surface parts: an outer surface and an inner surface. The outer surface is the surface that does not permanently contact the tooth surface. Conversely, the inner surface is the surface used to attach or fix the dental article to the tooth. If the dental article has the shape of a crown or inlay, the inner surface is usually concave, while the outer surface is usually convex. Dental articles should not contain components harmful to patient health and therefore should not contain hazardous or toxic components that can migrate from dental or orthodontic articles.

[0030] "Dental restoration" refers to dental products used to restore teeth in need of treatment. Examples of dental restorations include crowns, bridges, inlays, onlays, veneers, orthodontic products, and their components. The dental restorations described in this text do not have the shape of milled blocks.

[0031] Examples of orthodontic products include brackets, buccal tubes, attachments, traction hooks, and lingual buttons and their components.

[0032] "Monolithic zirconia ceramic dental restorations" refers to dental restorations that do not contain ceramic phases other than zirconia or hafnium oxide. Specifically, monolithic zirconia ceramic dental restorations do not contain glass or glass-ceramic materials or phases. Monolithic restorations contain crystalline phases of zirconia, wherein these phases may include soluble dopant ions that affect the composition, translucency, and color of the zirconia phase.

[0033] A "sol" is a continuous liquid phase containing discrete particles with sizes ranging from 1 nm to 100 nm or 1 nm to 50 nm, also known as a "colloidal solution." The sol described in this paper is translucent and does indeed exhibit the so-called "Tyndall effect" or "Tyndall scattering." The particle size is smaller than the wavelength of visible light (400 nm to 700 nm).

[0034] "Gel" refers to a wet, solid-like material in which a network of interconnected nanostructures spans the volume of a liquid medium. Gels are often primarily liquid in composition and typically exhibit liquid density, but possess solid-like cohesiveness. A sol can become a gel when solid nanoparticles dispersed in it can bind together to form a particle network that spans the liquid.

[0035] "Coloring component or ion" should mean a component or ion that has absorption in the visible spectrum (e.g., from about 380 nm to about 780 nm); produces a colored solution (visible to the human eye) if the coloring ion is dissolved in water (e.g., about 0.6 mol / L); and / or produces a coloring effect in zirconia articles containing coloring ions or components.

[0036] A translucent composition allows light to pass through partially, although it is not completely transparent, exhibiting significant volume scattering of transmitted light. The opposite property of translucency is opacity (O). (T = transmittance, I = intensity of transmitted light, I = intensity of light before transmission). Therefore, for a 1mm thick sheet with a diameter of 15mm, an opacity value less than approximately 0.9 is considered translucent (e.g., for measurements taken with the Colori7 device from X-Rite Corporation USA, measurement mode: reflection contrast ratio). Opacity can be measured in various ways: transmission, reflection, and reflection using the contrast ratio method.

[0037] "Particles" refers to solid matter with a geometrically measurable shape. The shape can be regular or irregular. Particles are typically analyzed in terms of, for example, particle size and particle size distribution.

[0038] The term "primary particle size" refers to the size of an unassociated individual particle (which is considered a primary particle).

[0039] If a dental ceramic article has undergone heat treatment (temperature range of 900°C to 1,100°C) for 1 to 3 hours, such that the green fracture strength of the dental ceramic, measured according to the "Three-Ball Stamping Test" ISO 6872:2015, is in the range of 15 MPa to 55 MPa or 30 MPa to 50 MPa, then the dental ceramic article is classified as "pre-sintered". Pre-sintered dental ceramic articles typically have a porous structure and are similar to fully sintered dental ceramic frames (typically 6.1 g / cm³ for 3 mol% yttrium-stabilized zirconia ceramics). 3 Compared to , its density (typically 3.0 g / cm³ for 3 mol% yttrium-stabilized zirconia ceramics) is lower. 3 (Lower)

[0040] "Ceramic zirconia articles" should mean three-dimensional articles in which at least one of the x, y, and z dimensions is at least about 5 mm, and the articles contain at least 80% or at least 90% by weight of zirconia.

[0041] "Ceramics" refers to inorganic non-metallic materials produced by applying heat. Ceramics are generally hard and brittle, and exhibit an inherently pure crystalline structure compared to glass or glass-ceramics.

[0042] "Crystallization" refers to a solid composed of atoms arranged in a three-dimensional periodic pattern (i.e., having a long-range crystal structure as determined by X-ray diffraction). Crystal structures include tetragonal, monoclinic, cubic zirconia, and mixtures thereof.

[0043] "Percolation" is a technique that uses ultrafiltration membranes to completely remove, replace, or reduce the concentration of salts or solvents from solutions containing organic molecules. This method selectively utilizes permeable (porous) membrane filters to separate components of solutions and suspensions based on molecular size.

[0044] The term "aerogel" should refer to a three-dimensional low-density solid (i.e., with a density less than 20% of that of an article having a porosity of less than 0.1% by volume). Aerogels are porous materials derived from gels in which the liquid component of the gel has been replaced by a gas. Solvent removal is typically carried out under supercritical conditions. In this process, the network does not shrink significantly, and a highly porous, low-density material is obtained.

[0045] Density refers to the ratio of an object's mass to its volume. The unit of density is usually g / cm³. 3 The density of an object can be calculated, for example, by determining its volume (e.g., by calculating or applying Archimedes' principle or method) and measuring its mass.

[0046] The term "tubular reactor" refers to the heated portion (i.e., the heating zone) of a continuous hydrothermal reactor system. Tubular reactors can be of any suitable shape. The shape of a tubular reactor is typically chosen based on the desired length of the reactor and the method used to heat it. For example, a tubular reactor can be straight, U-shaped, or coiled. The internal portion of a tubular reactor can be hollow or may contain baffles, spheres, or other known mixing techniques.

[0047] The term "calcination" refers to a method of heating a solid material to remove at least 90% by weight of volatile chemically bound components (e.g., organic components) (as opposed to drying, for example, in which physically bound water is removed by heating). Calcination is carried out at a temperature below that required for the pre-sintering step.

[0048] The terms "sintering" and "firing" are used interchangeably. Pre-sintered ceramic articles shrink during the sintering step (i.e., if sufficient temperature is applied). The sintering temperature to be applied depends on the ceramic material chosen. For zirconia-based ceramics, typical sintering temperatures range from 1,100°C to 1,550°C. Sintering typically involves densifying porous materials into materials with higher density and fewer pores (or materials with fewer voids). In some cases, sintering may also involve a change in the phase composition of the material (e.g., a partial conversion of an amorphous phase to a crystalline phase). Firing refers to the process of making objects from compressed powder by heating the material (usually below its melting point, i.e., solid-state sintering) until its particles adhere to each other.

[0049] "Additive manufacturing" refers to methods used to create three-dimensional artifacts. Examples of additive manufacturing technologies include vat polymerization, particularly stereolithography (SLA), digital light processing (DLP), continuous liquid interface production (CLIP), and volumetric additive manufacturing (VAM).

[0050] The artifacts can be in almost any shape or geometry and are generated from three-dimensional models or other electronic data sources.

[0051] “Environmental conditions” means the conditions under which the compositions described herein are typically subjected during storage and handling. Environmental conditions may be, for example, pressures of 900 mbar to 1,100 mbar, temperatures of 10°C to 40°C, and relative humidity of 10% to 100%. In the laboratory, environmental conditions are typically conditioned to 20°C to 25°C and 1,000 mbar to 1,025 mbar (at sea level).

[0052] As used herein, “an,” “a,” “the,” “at least one,” and “one or more” are used interchangeably. Also in this document, numerical ranges expressed by endpoints include all numbers contained within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc.).

[0053] Adding "plural form" to a term means that the term should include both singular and plural forms. For example, the term "additive" means one additive and multiple additives (e.g., 2, 3, 4, etc.).

[0054] Unless otherwise specified, all figures used in the specification and claims that indicate the quantity of components, the results of physical property measurements (such as those described below), etc., shall be understood to be modified by the term "about" in all cases.

[0055] When these terms appear in the specification and claims, the terms "comprising" or "including" and their variations are not restrictive. "Constitutes substantially of" means that specific additional components may be present, i.e., those components that do not substantially affect the essential properties of the article or composition. "Constitutes of" means that no additional components should be present. The term "comprising" should also include the terms "constantly of" and "constant of".

[0056] If a composition does not contain a certain component as an essential feature, then the composition is "substantially or substantially free of" said component. Therefore, the component itself, or in combination with other components or other components, will not be intentionally added to the composition. A composition that is substantially free of a certain component typically contains no such component at all. However, sometimes the presence of a small amount of said component is unavoidable, for example, due to impurities contained in the raw materials used.

[0057] The custom zirconia gel products, zirconia ceramic dental restorations, and manufacturing methods described herein are advantageous for a variety of reasons.

[0058] It has been found that, in order to achieve highly aesthetic dental restorations, it is advantageous to display a color gradient in the internal areas of the restoration and to have lower translucency, at least relative to some sections, than in the external areas.

[0059] The staining concept presented in this paper is better suited to the dental condition in the patient's mouth than applying staining liquid to the outer surface area of ​​the dental restoration.

[0060] Furthermore, it avoids unwanted diffusion-controlled color gradients from the outer surface area to the inner surface area of ​​the dental restoration.

[0061] It was also found that, in particular, the use of nanoscale zirconium oxide materials not only makes it easier to manufacture highly translucent products, but also allows for the use of lower sintering temperatures.

[0062] In contrast, dental restorations obtained by milling from pressed zirconia dental blanks have a larger average grain size and require higher sintering temperatures.

[0063] Furthermore, the present invention is capable of manufacturing dental restorations with vertically arranged colored areas.

[0064] This contrasts with dental restorations obtained by milling dental blanks with a color gradient, which has a fairly high level of layering.

[0065] Furthermore, dental restorations obtained from custom zirconia gel products allow for a more natural color gradient from the inner surface area to the outer surface area of ​​the dental restoration. These custom zirconia gel products contain two different gels and include a diffusion-controlled transition gel region between the two gels.

[0066] This invention can also manufacture personalized, i.e., customized dental restorations.

[0067] Based on its curvature, the convex surface of the outer surface region of the dental prosthesis corresponds to the concave inner surface of the corresponding mold used to receive the curable sol.

[0068] Similarly, the concave surface of the inner surface region of a dental restoration corresponds to the convex outer surface of the corresponding mold for receiving the curable sol.

[0069] The inner surface of this mold can be easily shaped or manufactured based on information associated with the patient's dental condition. Therefore, the process can utilize both geometric and tooth color data from an individual patient to design and produce restorations with excellent fit and aesthetics.

[0070] The present invention can also produce wire mesh dental restorations, especially dental restorations with thin sidewalls.

[0071] This invention relates to a custom-made zirconia gel product having the shape of a dental prosthesis.

[0072] Zirconia gel articles include a transition region containing a transition gel, wherein the transition region has a color gradient.

[0073] There are no particular restrictions on the shape of the transition area, but it is usually non-planar.

[0074] According to a more specific implementation, the customized zirconia gel article includes at least three regions: an inner surface region containing gel G1, an outer surface region containing gel G2, and a transition gel G... 1 / 2 The transition area.

[0075] Each region of a zirconia gel product originates from a solidified sol used to produce custom zirconia gel products and has substantially corresponding volumes.

[0076] The geometry of the inner surface, outer surface, or both, and the inner and outer surfaces of the corresponding areas, is typically based on information associated with the patient's dental condition. That is, the geometry of at least one of the surfaces of the zirconia gel article is customized.

[0077] The materials of the gel each contain

[0078] Crystalline zirconium oxide particles, Crystal phase stabilizer components, Cured organic components, especially radiation-cured organic components, Optional photoinitiator, Liquid, and Optional coloring components.

[0079] Using a radiation-curable sol containing radiation-curable components and a photoinitiator is generally preferred.

[0080] The phase stabilizer component is contained in the crystalline zirconia particles, and the optional coloring component may be contained in the crystalline zirconia particles or exist as a separate component.

[0081] At least one gel and transition gel contain a coloring component, wherein gel G1 differs from gel G2. One or more coloring components may be used if desired.

[0082] The transition gel is a mixture of materials composed of gel G1 and gel G2.

[0083] Similar to dental restorations that can be obtained from custom zirconia gel products, custom zirconia gel products can be in the shape of crowns, bridges, inlays, or facets.

[0084] However, custom-made zirconia gel products are typically larger than dental restorations, for example, at least twice the size in every dimension.

[0085] The transition area can be planar or non-planar. For highly personalized dental restorations, a non-planar transition gel area is preferred because such geometry generally better mimics the structure of natural teeth.

[0086] The content of coloring components in the transition region is usually lower than that in the inner surface region.

[0087] The present invention also relates to a method for producing custom zirconia gel products and related dental restorations as described herein.

[0088] For production, at least two different curable sols, sol S1 and sol S2, are used. Optionally and if required, additional sol S can be used. N , where N = 1, 2, 3, 4... or N = 1, 2, 3, 4... 10.

[0089] Place these sols in a mold with a non-planar inner bottom surface and / or place them on top of each other.

[0090] The application of the sol can be done manually or automatically, for example, with the help of a robot.

[0091] Placing the sol in a mold can be accomplished by a variety of methods, including casting, using inkjet printing technology, using gradient printing technology with groove polymerization, or any other suitable technology.

[0092] The non-planar inner bottom surface of a mold typically includes sections with concave, convex, or mixed concave / convex regions. Mixed concave / convex regions can be advantageous for producing dental restorations with so-called incisal tubercle waveform geometry.

[0093] Concave and / or convex areas are typically adapted to the shape of the tooth surface.

[0094] The non-planar bottom surface of the mold may include one or more segments whose shape is based on information associated with the patient's dental condition.

[0095] This shape is advantageous for manufacturing custom dental restorations.

[0096] Information associated with a patient’s dental condition is so-called digital data, which can be obtained and provided in a manner known to those skilled in the art, such as by taking or scanning a photograph of the dental condition in the patient’s mouth or by using information stored in a database.

[0097] Because the method described in this text is particularly suitable for producing individual dental restorations, the amount of sol used in this method is quite low.

[0098] Sol can be used in various amounts. For the production of custom dental restorations, only a small amount of sol is typically required.

[0099] The usable volume is in the range of 0.0001ml to 1ml or 0.01ml to 0.5ml.

[0100] Each sol is typically used in different volumes.

[0101] Typically, sol S1 is larger than sol S2 and larger than optional sol S N Use larger quantities, for example, ratios greater than 2 / 1, 5 / 1, or 10 / 1 in volume.

[0102] Sol S1 is typically used to form the outer surface area of ​​dental restorations; while sol S2 and optional sol S N To personalize the inner surface area of ​​a dental restoration, a small amount of material is typically required.

[0103] Sol S1, Sol S2 and optional Sol S N They differ from each other individually or in combination in the following properties: (i) the content of optional coloring components, (ii) the content of crystalline phase stabilizing components, and / or (iii) the content of crystalline zirconia particles, wherein properties (i) and (ii) and combinations of properties (i) and (ii) are sometimes preferred.

[0104] The method for producing custom zirconia gel articles may additionally include the following steps prior to step (a): Sols are available with varying amounts of stabilizing and / or coloring components. Mix at least two of these sols to obtain curable sol S1, curable sol S2, and optionally curable sol S N .

[0105] If needed, the curable sol S1, curable sol S2, and optional curable sol S can be adjusted. N The chemical composition is matched with information related to the patient's dental condition. This facilitates the production of even better, customized dental restorations.

[0106] If necessary, apply curable sol S2 and / or sol SN Place it so that it is in contact with the curable sol S1 only in one or more separate areas on the top surface of the sol S1.

[0107] If necessary, at least two different curable sols S 2,3 Place it so that it is in contact with the curable sol S1 only in one or more separate areas on the top surface of the sol S1.

[0108] Different colored zirconia sols can be used to achieve different colored surface areas.

[0109] This allows for the provision of custom dental products tailored to the individual conditions in a patient's mouth.

[0110] Applying a less opaque sol S1 to the inner surface of dental products can help mask the dark surface of the post without affecting the depth of reflection on the outer surface of the dental product.

[0111] The viscosity of each sol is typically around 50 mPa at 23°C. s to 3,000 mPa s or 60mPa s to 2,000 mPa Within the range.

[0112] This viscosity is found advantageous for several reasons: it facilitates the placement of the sol in a mold via casting or inkjet printing. The viscosity is low enough to allow for diffusion-controlled mixing of the sol in interfacial or transitional regions, resulting in a smooth color gradient from the inner to the outer surface. At the same time, the viscosity is high enough to avoid undesirable sol blending when the sol is placed in the mold.

[0113] If needed, sol S1, sol S2 and optional sol S N It can also be characterized by the following properties, either individually or in combination: For a 10mm optical path, it is semi-transparent in the wavelength range of 420nm to 600nm; For a 10mm optical path, it exhibits at least 5% transmittance at a wavelength of 420nm; It has a pH value in the range of 1 to 6.

[0114] It has been found that using translucent sols can improve the surface precision or detail resolution of ceramic products. Translucent sols exhibit less light scattering, which facilitates the polymerization of the curable components contained within the sol. Increased translucency allows for a shallower curing gradient, which also allows for more uniform curing throughout the structure, as curing with translucent materials requires a lower energy dose.

[0115] It was found that the transmittance was high enough within this range to allow for radiation curing of the sol within a sufficient time range to achieve the desired thickness.

[0116] The mold for casting sol has a non-planar internal bottom surface.

[0117] Because the dental prostheses described in this text are custom-made, the corresponding molds used to produce the dental prostheses are also custom-made, especially regarding their internal bottom surfaces.

[0118] Depending on the requirements, the mold or internal bottom surface can be produced using a variety of technologies, including thermoforming, 3D printing, or casting, for example, by laboratory replication techniques in silicone rubber, hydrocolloids, etc.

[0119] Dental thermoforming works by applying heat and pressure to a plastic sheet placed on top of a 3D model specifically produced for that patient (e.g., using additive manufacturing techniques).

[0120] Alternatively, molds can be directly produced via additive manufacturing using information associated with the patient's dental condition.

[0121] Available additive manufacturing technologies include trench polymerization, stereolithography (SLA), digital light processing (DLP), robotic paste direct writing (RC), material jetting (MJ), binder jetting (BJ), and volumetric additive manufacturing (VAM).

[0122] Information relating to a patient's dental condition can be obtained using, for example, an intraoral scanner. Various intraoral scanners are commercially available (e.g., from 3Shape, Planmeca, etc.). Alternatively, information can be obtained from and matched with data stored in a dental bank.

[0123] Similarly, if needed, this can be achieved by using a tooth shade guide (e.g., VITA Toothguide 3D-MASTER). ™ ) or electronic devices (e.g., VITA Easyshade) ™ LITE, 3Shape Trios ™ 3) Determine the appropriate tooth color.

[0124] The design and manufacturing process may also include computer-aided design (CAD) and / or computer-aided manufacturing (CAM). Mold dimensions are typically scaled up to account for shrinkage between the casting process and subsequent binder removal and sintering processes.

[0125] Any suitable material for the mold can be used. Suitable materials include PET and polyurethane. Alternatively, the mold can be formed by casting silicone rubber or hydrocolloids or other conventional dental laboratory replication materials.

[0126] The mold may be a brittle (e.g., polymer) or biodegradable (e.g., wax) material to accommodate the undercut features.

[0127] The mold can be a single component or assembled from multiple components, and may include parting lines, sliders, etc. to accommodate production and reuse.

[0128] Curable sol contains: Crystalline zirconium oxide particles, preferably in an amount of 25% to 65% by weight. The crystal phase stabilizer component is preferably present in an amount of 2 mol% to 8 mol% of oxides relative to the total crystalline oxide particles. The curable organic component, preferably in an amount of 2% to 30% by weight, is preferred. The optional photoinitiator is preferably present in an amount of 0.01% to 3% by weight. Liquid, preferably in an amount of 25% to 70% by weight. The optional coloring ions are preferably present in amounts from 0% to 2% by weight. The optional inhibitor component is preferably present in an amount of 0% to 0.5% by weight. The weight percentage is relative to the weight of the curable sol, wherein the phase stabilizer component and / or optional coloring ions may also be included in the crystalline zirconia particles.

[0129] The crystalline zirconium oxide particles in the sol typically have a primary particle size in the range of 2 nm to 50 nm (in some embodiments, 5 nm to 50 nm, 2 nm to 25 nm, 5 nm to 25 nm, 2 nm to 15 nm, or even 5 nm to 15 nm).

[0130] Crystalline zirconia particles are typically present in the following amounts: at least 25% by weight or at least 30% by weight or at least 35% by weight; up to 65% by weight or up to 60% by weight or up to 55% by weight; 25% to 65% by weight, or 30% to 60% by weight, or 35% to 55% by weight; % by weight is relative to the weight of the sol.

[0131] Using a sol with a high content of crystalline zirconia particles is advantageous because it reduces the amount of liquid removal required in subsequent processes. Therefore, a crystalline zirconia particle content in the range of 35% to 65% by weight is preferred.

[0132] The crystalline phase stabilizing components that can be used include those selected from Ce, Mg, Ca, Y, La, rare earth element ions or combinations thereof, wherein the use of Y is sometimes preferred.

[0133] The phase stabilizer component, calculated as an oxide, is typically present in the following amounts: at least 2 mol%, at least 3 mol%, or at least 4 mol%; at most 7 mol%, at most 6 mol%, or at most 5 mol%; 2 mol% to 7 mol%, or 3 mol% to 6 mol%, or 4 mol% to 5 mol%; mol% is relative to the total crystalline oxide particles.

[0134] In order to act as a crystal phase stabilizer, the crystal phase stabilizing component is usually included in crystalline zirconia products.

[0135] The curable organic components present in the sol can be described as a first monomer, a second monomer, a third monomer, etc.

[0136] If desired, the zirconia particles that have been surface-modified with a polymerizable agent can be polymerized to provide a composition comprising cross-linked zirconia particles.

[0137] The first monomer can be used as a polymerizable surface modifier. A variety of first monomers can be used.

[0138] The surface modifier can be represented by formula AB, wherein the A group can be attached to the surface of the zirconium oxide-based particles, and the B group is radiation-curable.

[0139] Group A can be attached to the surface of zirconium-based particles by adsorption, ionic bonding, covalent bonding, or a combination thereof.

[0140] Examples of group A include acidic moieties (such as carboxylic acid groups, phosphate groups, sulfonic acid groups and their anions) and silanes.

[0141] Group B contains a radiation-curable portion.

[0142] Examples of group B include vinyl groups, particularly acryloyl or methacryloyl moieties.

[0143] Suitable surface modifiers include polymerizable carboxylic acids and / or their anions, polymerizable sulfonic acids and / or their anions, polymerizable phosphoric acids and / or their anions, and polymerizable silanes. Suitable surface modifiers are also described, for example, in WO 2009 / 085926 A1 (Kolb et al.).

[0144] Examples of free radical polymerizable surface modifiers are polymerizable surface modifiers containing an acidic moiety or its anion (e.g., a carboxylic acid group).

[0145] Exemplary free radical polymerizable acidic surface modifiers include acrylic acid, methacrylic acid, β-carboxyethyl acrylate, and mono-2-(methacryloyloxyethyl) succinate.

[0146] Exemplary free-radical polymerizable surface modifiers may be reaction products of hydroxyl-containing polymerizable monomers and cyclic acid anhydrides (such as succinic anhydride, maleic anhydride, and phthalic anhydride). Exemplary hydroxyl-containing polymerizable monomers include hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, and hydroxybutyl methacrylate. Acryloyloxy and methacryloxy-functionalized polyethylene oxides and polypropylene oxides may also be used as hydroxyl-containing polymerizable monomers.

[0147] An exemplary free radical polymerizable surface modifier for imparting both polarity and reactivity to zirconium oxide nanoparticles is succinate mono(methacryloyloxy polyethylene glycol).

[0148] Another example of a surface modifier that can be polymerized by free radicals is a polymerizable silane.

[0149] Exemplary polymerizable silanes include: methacryloxyalkyltrialkoxysilanes or acryloyloxyalkyltrialkoxysilanes (e.g., 3-methacryloyloxypropyltrimethoxysilane, 3-acryloyloxypropyltrimethoxysilane, and 3-(methacryloyloxy)propyltriethoxysilane); methacryloxyalkylalkyldialkoxysilanes or acryloyloxyalkyl-alkyldialkoxysilanes (e.g., 3-(methacryloyloxy)propylmethyldimethoxysilane and 3-(acryloyloxypropyl)methyldimethoxysilane); methacryloxyalkyldialkylalkoxysilanes or acryloyl... alkyl-dialkyl-alkoxysilanes (e.g., 3-(methacryloyloxy)propyldimethylethoxysilane); mercaptoalkyltrialkoxysilanes (e.g., 3-mercaptopropyltrimethoxysilane); aryltrialkoxysilanes (e.g., styrylethyltrimethoxysilane); vinylsilanes (e.g., vinylmethyldiacetoxysilane, vinyldimethylethoxysilane, vinylmethyl-diethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, vinyl-triisopropoxysilane, and vinyltri(2-methoxyethoxy)silane).

[0150] According to one embodiment, the sol described herein comprises one or more second monomers, each comprising at least two radiation-curable portions. These second monomers may act as crosslinking agents during the gel formation step.

[0151] Any suitable second monomer that does not have surface-modifying groups can be used. That is, the optional second monomer does not have carboxylic acid groups or silane groups. The second monomer is typically a polar monomer (e.g., a non-acidic polar monomer), a monomer having multiple polymerizable groups, an alkyl (meth)acrylate, or a mixture thereof.

[0152] The presence of monomers with multiple polymerizable groups tends to enhance the strength of the gel composition formed during sol polymerization.

[0153] The number of polymerizable groups can range from 2 to 6 or even more. In many embodiments, the number of polymerizable groups ranges from 2 to 5 or 2 to 4. The polymerizable group is typically a (meth)acryloyl group.

[0154] Exemplary monomers having two (meth)acryloyl groups include: 1,2-ethylene glycol diacrylate, 1,3-propanediol diacrylate, 1,9-nonanediol diacrylate, 1,12-dodecanediol diacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, butanediol diacrylate, bisphenol A diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, tripropylene glycol diacrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, polyethylene / polypropylene copolymer diacrylate, polybutadiene di(meth)acrylate, propoxylated glycerol tri(meth)acrylate, and neopentyl glycol hydroxypentyl ester diacrylate modified caprolactone.

[0155] Exemplary monomers having three or four (meth)acryloyl groups include: trimethylolpropane triacrylate (e.g., as TMPTA-N) ™ From Cytec Industries, Inc. (Smyrna, GA, USA), and as SR-351 ™ Obtained commercially from Sartomer (Exton, PA, USA), pentaerythritol triacrylate (e.g., as SR-444). ™ Purchased from Satormo), ethoxylated (3) trimethylolpropane triacrylate (e.g., available as SR-454) ™ Obtained from Satormo), ethoxylated (4) pentaerythritol tetraacrylate (e.g., as SR-494) ™ Obtained from Satormo), tris(2-hydroxyethyl isocyanurate) triacrylate (e.g., available as SR-368) ™(obtained from Satormo), a mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate (e.g., available from Cytec Industries, as PETIA) ™ It has an approximately 1:1 ratio of tetraacrylate to triacrylate, and is marketed under the trade name PETA-K. ™ It has a tetraacrylate to triacrylate ratio of approximately 3:1, and pentaerythritol tetraacrylate (for example, it can be used as SR-295). ™ Obtained from Satormo) and di-trimethylolpropane tetraacrylate (e.g., available as SR-355) ™ (Originated from Satormo).

[0156] Exemplary monomers having five or six (meth)acryloyl groups include dipentaerythritol pentaacrylate (e.g., as SR-399). ™ Obtained from Satormo) and hexafunctional polyurethane acrylate (e.g., available as CN975) ™ (Originated from Satormo).

[0157] In some embodiments, the optional second monomer is a polar monomer. As used herein, the term "polar monomer" refers to a monomer having a free radical polymerizable group and a polar group. The polar group is typically non-acidic and typically contains a hydroxyl group, a primary amide group, a secondary amide group, a tertiary amide group, an amino group, or an ether group (i.e., a group containing at least one alkylene-oxy-alkylene group of the formula -ROR-, wherein each R is an alkylene group having 1 to 4 carbon atoms).

[0158] Suitable optional polar monomers having a hydroxyl group include, but are not limited to: hydroxyalkyl (meth)acrylates (e.g., 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate), and hydroxyalkyl (meth)acrylamides (e.g., 2-hydroxyethyl (meth)acrylamides or 3-hydroxypropyl (meth)acrylamides), ethoxylated hydroxyethyl (meth)acrylates (e.g., as CD570). ™ CD571 ™ and CD572 ™ Monomers commercially available from Satormo, Exxon, Pennsylvania, USA, and aryloxy-substituted hydroxyalkyl esters of (meth)acrylate (e.g., 2-hydroxy-2-phenoxypropyl methacrylate).

[0159] Exemplary polar monomers having a primary amide group include (meth)acrylamide. Exemplary polar monomers having a secondary amide group include, but are not limited to, N-alkyl (meth)acrylamides, such as N-methyl (meth)acrylamide, N-ethyl (meth)acrylamide, N-isopropyl (meth)acrylamide, N-tert-octyl (meth)acrylamide, and N-octyl (meth)acrylamide. Exemplary polar monomers having a tert-amide group include, but are not limited to: N-vinylcaprolactam, N-vinyl-2-pyrrolidone, (meth)acryloylmorpholine; and N,N-dialkyl (meth)acrylamides, such as N,N-dimethyl (meth)acrylamide, N,N-diethyl (meth)acrylamide, N,N-dipropyl (meth)acrylamide, and N,N-dibutyl (meth)acrylamide.

[0160] Polar monomers having an amino group include various N,N-dialkylaminoalkyl (meth)acrylates and N,N-dialkylaminoalkyl (meth)acrylamides. Examples include, but are not limited to: N,N-dimethylaminoethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylamide, N,N-dimethylaminopropyl (meth)acrylate, N,N-dimethylaminopropyl (meth)acrylamide, N,N-diethylaminoethyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylamide, N,N-diethylaminopropyl (meth)acrylate, and N,N-diethylaminopropyl (meth)acrylamide.

[0161] Exemplary polar monomers having ether groups include, but are not limited to: alkoxylated alkyl (meth)acrylates, such as ethoxyethoxyethyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, and 2-ethoxyethyl (meth)acrylate; and poly(epoxyalkylene)(meth)acrylates, such as poly(ethylene oxide)(meth)acrylate and poly(propylene oxide)(meth)acrylate. Poly(epoxyalkylene)acrylates are commonly referred to as poly(alkylene glycol)(meth)acrylates. These monomers may have any suitable end groups, such as hydroxyl or alkoxy groups. For example, when the end group is a methoxy group, the monomer may be referred to as methoxy poly(ethylene glycol)(meth)acrylate.

[0162] Suitable alkyl (meth)acrylates that can be used as a second monomer may have alkyl groups having a straight-chain, branched, or cyclic structure. Examples of suitable alkyl (meth)acrylates include, but are not limited to: methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, n-pentyl (meth)acrylate, 2-methylbutyl (meth)acrylate, n-hexyl (meth)acrylate, cyclohexyl (meth)acrylate, 4-methyl-2-pentyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 2-methylhexyl (meth)acrylate, n-octyl (meth)acrylate, and methyl propylene. Isooctyl acrylate, 2-octyl acrylate, isononyl acrylate, isoamyl acrylate, 3,3,5-trimethylcyclohexyl acrylate, n-decyl acrylate, isodecyl acrylate, isobornyl acrylate, 2-propylheptyl acrylate, isotridecyl acrylate, isostearyl acrylate, octadecyl acrylate, 2-octyldecyl acrylate, dodecyl acrylate, lauryl acrylate, and heptadecanyl acrylate.

[0163] In some embodiments, the second monomer may be characterized by the following parameters, alone or in combination: (i) soluble in the liquid contained in the sol; (ii) having at least one, two, or three curable portions; (iii) having a radiation-curable portion selected from vinyl, acryloyl, or methacryloyl moieties; (iv) molecular weight (Mw): 70 g / mol to 5,000 g / mol; or 70 g / mol to 1,000 g / mol; or 100 g / mol to 500 g / mol, wherein parameters (ii) and (iii), or (ii) and (iv), or a combination of (ii), (iii), and (iv) are sometimes preferred.

[0164] Using radiation-curable components with molecular weights within the above range, as described above, is advantageous for providing sols with the desired viscosity. Lower molecular weight components are also generally more soluble than higher molecular weight components.

[0165] The curable component is typically present in the following amounts: at least 2% by weight or at least 5% by weight or at least 10% by weight; up to 30% by weight or up to 25% by weight or up to 20% by weight; 2% to 30% by weight, or 5% to 25% by weight, or 10% to 20% by weight; % by weight is relative to the weight of the sol.

[0166] The sol described herein contains one or more photoinitiators.

[0167] There are no particular restrictions on the properties and structure of photoinitiators, unless the desired results cannot be achieved.

[0168] In some embodiments, the photoinitiator can be characterized by at least one or more, and sometimes all of, the following parameters: solubility in the liquid contained in the sol; and / or radiation absorption in the range of 200 nm to 500 nm or 300 nm to 450 nm.

[0169] Photoinitiators should be able to initiate or trigger the curing or hardening reaction of radiation-curable components present in the sol.

[0170] The following categories of photoinitiators can be used: a) two-component systems in which radicals are generated by abstracting hydrogen atoms from a donor compound; b) one-component systems in which two radicals are generated by cleavage.

[0171] Examples of photoinitiators of type (a) typically contain a moiety selected from benzophenone, xanthonone, or quinone in combination with an aliphatic amine.

[0172] Examples of photoinitiators of type (b) typically contain a moiety selected from benzoin ether, acetophenone, benzoyl oxime, or acylphosphine.

[0173] Exemplary UV initiators include 1-hydroxycyclohexylbenzophenone (previously known as IRGACURE 184). ™ Purchased from Ciba Specialty Chemicals Corp., 4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-propyl)one (formerly IRGACURE 2529) ™ Purchased from Sibat Specialty Chemicals, 2-hydroxy-2-methylphenylacetone (formerly known as DAROCURE D111) ™ Purchased from Sibat Specialty Chemicals Co., Ltd.) and bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (formerly IRGACURE 819) ™ Purchased from Sibat Chemicals Company.

[0174] Photoinitiators are typically present in the following amounts: at least 0.01% by weight or at least 0.1% by weight or at least 0.2% by weight; at most 3% by weight or at most 2% by weight or at most 1% by weight; from 0.01% by weight to 3% by weight, or from 0.1% by weight to 2% by weight, or from 0.2% by weight to 1% by weight; % by weight is relative to the weight of the sol.

[0175] The properties and structure of the liquid are not particularly limited unless the desired results cannot be achieved. In some embodiments, the solvent can be characterized by the following characteristics, alone or in combination: a) Boiling point: above 100℃ or above 120℃ or above 150℃; b) Molecular weight: 25 g / mol to 300 g / mol; c) Viscosity: 0.2 mPa s to 10mPa s (23℃); d) Miscible with water; e) Soluble in supercritical carbon dioxide or liquid carbon dioxide.

[0176] The following combinations of features are sometimes preferred: a) and b), or a), b) and c), or a), b), c) and d).

[0177] Using liquids with boiling points above 100°C or 150°C can be advantageous in reducing liquid evaporation during the process.

[0178] Using liquids with molecular weights and / or viscosities within the aforementioned range is beneficial, as it helps to adjust the viscosity of the sol. Molecular weight also affects the diffusion constant and the ease with which the liquid can be removed.

[0179] Using mixtures of different liquids can be beneficial because it allows for adjustment of viscosity or post-processing properties, such as removing excess sol after casting.

[0180] During other processing steps required to produce ceramic products, the liquid should also be easily removable.

[0181] Furthermore, the liquid should not interfere with or negatively affect the polymerization of the curable components present in the sol.

[0182] In this regard, it is advantageous to use liquids that do not contain polymerizable components.

[0183] To enhance the solubility or properties of a liquid, it typically contains one or more polar moieties, including ether, alcohol, or carboxyl groups.

[0184] According to one embodiment, the liquid is typically a glycol or polyglycol, a monoether glycol or a monoether polyglycol, a diether glycol or a diether polyglycol, an ether ester glycol or an ether ester polyglycol, a carbonate, an amide or a sulfoxide (e.g., dimethyl sulfoxide).

[0185] Suitable diols or polydiols, monoether diols or monoether polydiols, diether diols or diether polydiols, and ether ester diols or ether ester polydiols generally have the following formula (I).

[0186]

[0187] In equation (I), each R 1Independently, it can be hydrogen, alkyl, aryl, or acyl. Suitable alkyl groups typically have 1 to 10, 1 to 6, or 1 to 4 carbon atoms. Suitable aryl groups typically have 6 to 10 carbon atoms and are usually phenyl or phenyl substituted with an alkyl group having 1 to 4 carbon atoms. Suitable acyl groups typically have the formula -(CO)R. a , where R a It is an alkyl group having 1 to 10 carbon atoms, 1 to 6 carbon atoms, 1 to 4 carbon atoms, 2 carbon atoms, or 1 carbon atom. The acyl group is usually an acetyl group (-(CO)CH3). In formula (I), each R 2 Typically ethylidene or propyleneide. The variable n is at least 1 and can be in the range of 1 to 10, 1 to 6, 1 to 4, or 1 to 3.

[0188] The diol or polydiol of formula (I) has two Rs equal to hydrogen atoms. 1 Group. Examples of diols include, but are not limited to, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, and tripropylene glycol.

[0189] The monoether diol or monoether polydiol of formula (I) has a first R equal to that of hydrogen. 1 The group and the second R equal to alkyl or aryl 1 Group. Examples of monoether diols or monoether polydiols include, but are not limited to, ethylene glycol monohexyl ether, ethylene glycol monophenyl ether, propylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, diethylene glycol monohexyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl ether, tripropylene glycol monomethyl ether, and tripropylene glycol monobutyl ether.

[0190] The diether diol or diether polydiol of formula (I) has two R groups equal to alkyl or aryl groups. 1 Group. Examples of diether diols or diether polydiols include, but are not limited to, ethylene glycol dipropyl ether, ethylene glycol dibutyl ether, dipropylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether and pentaethylene glycol dimethyl ether.

[0191] The ether ester diol or ether ester polydiol of formula (I) has a first R equal to alkyl or aryl. 1 The second R group equal to the acyl group 1 Group. Examples of ether ester diols or ether ester polydiols include, but are not limited to, ethylene glycol butyl ether acetate, diethylene glycol butyl ether acetate, and diethylene glycol ethyl ether acetate.

[0192] Other suitable organic solvents are carbonates of formula (II).

[0193]

[0194] In equation (II), R 3 It is hydrogen or an alkyl group, such as an alkyl group having 1 to 4 carbon atoms, 1 to 3 carbon atoms, or 1 carbon atom. Examples include ethylene carbonate and propylene carbonate.

[0195] Other suitable organic solvents are amides of formula (III).

[0196]

[0197] In formula (III), group R 4 It is hydrogen, alkyl, or related to R 5 The elements are combined to form a quinary ring, which includes connections to R. 4 carbonyl group and connected to R 5 The nitrogen atom. Group R 5 It is hydrogen, alkyl, or related to R 4 The elements are combined to form a quinary ring, which includes connections to R. 4 carbonyl group and connected to R 5 The nitrogen atom. Group R 6 It is hydrogen or alkyl. Used in R 4 R 5 and R 6 Suitable alkyl groups have 1 to 6 carbon atoms, 1 to 4 carbon atoms, 1 to 3 carbon atoms, or 1 carbon atom. Examples of amide organic solvents of formula (III) include, but are not limited to, formamide, N,N-dimethylformamide, N,N-dimethylacetamide, N,N-diethylacetamide, N-methyl-2-pyrrolidone, and N-ethyl-2-pyrrolidone.

[0198] Specific examples of solvents that may be used include: monohydric alcohols (e.g., C2 to C8 alcohols, including primary, secondary, and tertiary alcohols), polyhydric alcohols (e.g., ethylene glycol, propylene glycol, glycerol), and diethylene glycol ethyl ether (Carbitol). ™ ), 1-methoxy-2-propanol, N-methylpyrrolidone, acetonitrile, chlorobenzene, 1,4-dimethylbenzene, ethyl acetate, methyl ethyl ketone, tetrahydrofuran, toluene, xylene, and mixtures thereof.

[0199] The following solvents are sometimes preferred: ethanol, 1-methoxy-2-propanol, N-methylpyrrolidone, diethylene glycol ethyl ether, and mixtures thereof. In some cases, suitable solvents may also include low-boiling alcohols (below 100°C; such as methanol, ethanol, propanol) and mixtures thereof, or preferably the same solvents described above.

[0200] The liquid is typically present in the following amounts: at least 25% by weight or at least 30% by weight or at least 35% by weight; up to 70% by weight or up to 65% by weight or up to 60% by weight; 25% to 70% by weight, or 30% to 65% by weight, or 35% to 60% by weight; weight% is relative to the weight of the sol.

[0201] The coloring components that can be used include those containing ions selected from Fe, Mn, Er, Pr, Tb, Cr, Co, Mo and / or Nd.

[0202] If these components are present, they are typically found as oxides in sintered products.

[0203] Coloring ions are typically present in the following amounts: 0% by weight, or at least 0.1% by weight, or at least 0.2% by weight; up to 2% by weight, or up to 1% by weight, or up to 0.8% by weight; 0% by weight to 2% by weight, or 0.1% by weight to 1% by weight, or 0.2% by weight to 0.8% by weight; % by weight is the total amount of coloring ions relative to the weight of the sol.

[0204] According to another embodiment, the sol described in this text contains one or more inhibitors.

[0205] There are no particular restrictions on the nature and structure of inhibitors, unless the desired results cannot be achieved.

[0206] Inhibitors can extend the shelf life of sols, help prevent unwanted side reactions, and regulate the polymerization process of radiation-curable components present in the sol.

[0207] Adding one or more inhibitors to the sol can also help improve the precision or detail resolution of the ceramic surface.

[0208] In particular, it has been found that adding inhibitors to the printing sols described in this text can help improve the resolution and accuracy of the SLA process, as well as extend the shelf life of the sols, by reducing or avoiding unwanted scattering effects.

[0209] The inhibitor should be soluble in the solvent contained in the sol. Usable inhibitors typically contain a phenolic moiety.

[0210] Specific examples of inhibitors that may be used include: butylated hydroxytoluene (Ionol), p-methoxyphenol (MOP), hydroquinone monomethyl ether (MEHQ), 2,6-di-tert-butyl-4-methylphenol (BHT), phenothiazine, 2,2,6,6-tetramethylpiperidine-1-oxy radical (TEMPO), and mixtures thereof.

[0211] Inhibitors are typically present in the following amounts: 0% by weight, or at least 0.001% by weight, or at least 0.01% by weight; up to 0.5% by weight, or up to 0.02% by weight, or up to 0.01% by weight; 0% by weight to 0.5% by weight, or 0.001% by weight to 0.05% by weight, or 0.01% by weight to 0.02% by weight; % by weight is relative to the weight of the sol.

[0212] Generally, the sol described in this text can be obtained as follows: Provides a starting sol containing nano-sized zirconium oxide particles.

[0213] The precursor solution is typically prepared by mixing a zirconium salt (e.g., acetate) solution with a solvent (e.g., water). A phase stabilizer (e.g., yttrium acetate) is added and dissolved in the precursor solution. The resulting composition is pumped through, for example, a hydrothermal reactor. Suitable hydrothermal reactors are described, for example, in US 5,453,262 (Dawson et al.) and US 5,652,192 (Matson et al.).

[0214] When subjected to hydrothermal treatment, various dissolved salts undergo hydrolysis and condensation reactions to form zirconium oxide-based particles. These reactions are typically accompanied by the release of acidic byproducts, such as acetic acid.

[0215] The content of tetragonal and / or cubic phases in zirconia microcrystals can be adjusted by changing the amount of phase-stabilizing components added during the production process.

[0216] The starting sol is usually concentrated.

[0217] To obtain a more concentrated sol, at least a portion of the water-based medium is removed from the zirconium oxide-based sol.

[0218] According to one implementation, the zirconium oxide-based sol undergoes dialysis or filtration.

[0219] The content of crystalline nano-sized zirconium oxide particles in the concentrated starting sol is typically in the range of 25% to 65% by weight.

[0220] In some implementations, the zirconium oxide-based sol can undergo a solvent exchange process.

[0221] An organic liquid with a boiling point higher than water can be added to the effluent. Examples of suitable organic liquids for solvent exchange methods include 1-methoxy-2-propanol, N-methylpyrrolidone, or diethylene glycol ethyl ether. The water can then be removed by methods such as distillation, rotary evaporation, or oven drying.

[0222] Zirconia-based sols contain zirconia-based particles dispersed and / or suspended (i.e., dispersed, suspended, or a combination thereof) in an aqueous / organic matrix.

[0223] Add other components to the starting sol: curable components, photoinitiators, optional organic dyes, inhibitors, coloring components, and other additives (if needed).

[0224] Sol preparation is usually carried out under safe light conditions to avoid undesirable premature polymerization.

[0225] Sol S1, Sol S2 and optional Sol S N It can also be produced by mixing so-called masterbatches with different contents of stabilizing components and / or coloring components.

[0226] As a sol used for producing custom dental restorations, the curable sol S1, curable sol S2, and optional curable sol S can be adjusted if desired. N The chemical composition is used to match information associated with the patient's dental condition.

[0227] Therefore, depending on the desired color of the custom dental restoration to be produced, different amounts of masterbatches of different colors can be mixed to obtain sol S1, sol S2, and optional sol S N .

[0228] At least sol S2 contains coloring components, and typically sol S2 has lower light transmittance than sol S1.

[0229] In addition, sol S1, sol S2 and optional sol S N They differ from each other individually or in combination in the following properties: (i) the content of coloring components, (ii) the content of crystal phase stabilizer components, (iii) the content of crystalline zirconia grains, and (iv) viscosity; wherein combinations of (i) and (ii), or (i) and (iii), or (ii) and (iii) are sometimes preferred.

[0230] In some implementations, the viscosity difference between the sols is typically greater than a ratio of at least 1.2, 1.5, or 2.

[0231] Methods for producing custom zirconia gel products also include a curing step, particularly a radiation curing step.

[0232] Radiation curing is typically performed under the following conditions: wavelength: 300 nm to 500 nm, or 365 nm to 460 nm; duration: 1 s to 5 min; temperature: 10 °C to 30 °C.

[0233] By performing a radiation curing step, the curable components contained in the sol are at least partially cross-linked, thereby forming a gel product.

[0234] The methods described herein may also include a post-curing step.

[0235] If necessary, zirconia gel products can be post-cured by applying radiation or heat.

[0236] Such steps help to improve the stability of zirconia gel products by further increasing the degree of polymerization.

[0237] If a post-curing step is present, the post-curing step can be characterized by the following features, alone or in combination: (i) the application of radiation with a wavelength of 200 nm to 500 nm or 350 nm to 450 nm; (ii) the application of a heating step at a temperature below the temperature at which drying occurs or at the temperature used for debonding or calcination; for example, 30 °C to 110 °C or 40 °C to 80 °C.

[0238] A post-curing step is typically performed after the radiation curing step of the curable zirconia sol.

[0239] To produce dental restorations, the method may include additional steps.

[0240] These steps can produce intermediate products, such as aerogel products and / or pre-sintered zirconia products.

[0241] Another step may involve converting zirconia gel products into zirconia aerogel products.

[0242] The conversion step can be achieved through a method that includes an extraction step.

[0243] Zirconia aerogel articles are formed by removing liquid from zirconia gel articles without excessive shrinkage (e.g., not exceeding about 30% or 40% by volume).

[0244] If water is present, it can be removed from the zirconia gel article, for example, via alcohol exchange, to provide a gel that is at least partially dehydrated. Then, if alcohol is present, the zirconia gel article is converted or transformed into a zirconia aerogel article by removing the alcohol from the partially dehydrated zirconia gel article, for example, via supercritical extraction.

[0245] If desired, zirconia aerogel products can be characterized by the following characteristics, alone or in combination: (a) Contains crystalline zirconium oxide particles having an average primary particle size in the range of 2 nm to 50 nm, 2 nm to 30 nm, or 2 nm to 20 nm; (b) Content of crystalline zirconium oxide particles: at least 85 mol% (c) It has an organic content of at least 3% by weight or in the range of 3% to 40% by weight; (d) The lengths of both x, y, and z dimensions: at least 1 mm, at least 2 mm, or at least 3 mm; (e) Density: 0.5 g / cm³3 Up to 1.5g / cm 3 .

[0246] Features (a) and (b), or (a), (b) and (c), or (b), (d) and The combination of these can be considered preferred.

[0247] If applied, the extraction step can be characterized by the following features, either individually or in combination: (a) Temperature: 20°C to 100°C or 30°C to 80°C or 15°C to 150°C; (b) Pressure: 5 MPa to 200 MPa or 10 MPa to 100 MPa or 1 MPa to 20 MPa or 5 MPa to 15 MPa; (c) Duration: 2h to 175h or 5h to 25h or 1h to 5h; (d) Extraction or drying medium: carbon dioxide in its supercritical stage.

[0248] The combination of features (a), (b) and (d) is sometimes preferred.

[0249] By performing a supercritical extraction step, most of the liquid in the printed gel product can be removed.

[0250] In some embodiments, the aerogel contains some residual organic liquid. The residual liquid may be up to 6% by weight based on the total weight of the aerogel article. For example, the aerogel article may contain up to 5% by weight, up to 4% by weight, up to 3% by weight, up to 2% by weight, or up to 1% by weight of organic liquid.

[0251] The removal of the organic liquid results in the formation of pores within the dried structure. Preferably, the pores are large enough to allow gases from the decomposition products of the polymer material to escape without causing the structure to crack when the dried structure is further heated to burn off the organic material and form a sintered article.

[0252] To produce dental restorations, the method also includes one or more heat treatment steps.

[0253] Depending on the heat treatment conditions, heat treatment can produce calcined dental zirconia products, pre-sintered dental zirconia products, or sintered dental zirconia products.

[0254] Heat treatment can be performed in one or more steps and at different locations.

[0255] To obtain calcined dental zirconia products, a heating step is performed to remove organic residues remaining in the zirconia product before final sintering. Removing organic residues before sintering reduces the risk of cracking during sintering.

[0256] The heating process is typically carried out at temperatures below 800°C, 700°C, or 600°C. Typical temperature ranges are 400°C to 800°C or 500°C to 700°C.

[0257] This heating step typically takes the time required to burn off the organic components in a zirconia product. Typical time ranges are 5 to 100 hours or 10 to 50 hours.

[0258] To obtain pre-sintered dental zirconia articles, the following conditions are typically applied, either alone or in combination: (i) temperature: 900°C to 1,100°C, 950°C to 1,090°C, or 975°C to 1,080°C; (ii) atmosphere: air or an inert gas (e.g., nitrogen, argon); (iii) residence time: 0 h to 24 h, or 0.1 h to 5 h; (iv) duration: until 40% to 60% of the density of the sintered material has been reached.

[0259] Combinations of conditions (i) and (ii), or (i) and (iii), or (i) and (iv), or (i) and (ii) and (iv) are sometimes preferred.

[0260] Residence time (i.e., the time the aerogel article is held at that temperature) also helps to adjust strength and / or hardness according to the specific needs of the selected machining technique. If the residence time is too long, the dental article may become too hard to be machined under suitable conditions, if necessary.

[0261] To obtain sintered dental zirconia articles, the following conditions are typically applied: (i) temperature: 1,100°C to 1,350°C or 1,200°C to 1,300°C; (ii) atmosphere: air or an inert gas (e.g., nitrogen, argon); (iii) duration: until the porosity of the zirconia article is less than 0.1% by volume or less than 0.05% by volume; (iv) residence time: 1 h to 24 h or 2 h to 12 h; (v) pressure: ambient pressure.

[0262] Conditions (i) and (iii), or (i) and (v), or combinations of (i), (iii) and (v) are sometimes preferred.

[0263] However, it is also possible to first provide pre-sintered dental zirconia products, which are then sintered later into sintered dental zirconia products. This can be done at different locations if desired.

[0264] During the heating step, the porous dental ceramic article is sintered into its final shape, thereby changing its dimensions, density, hardness, flexural strength and / or grain size.

[0265] Heating temperature and residence time (i.e., the period of time during which a specific temperature is maintained) are usually related. Higher temperatures typically require only shorter residence times.

[0266] Depending on the applied heating rate, the heat treatment step can be characterized as conventional firing conditions (e.g., heating rates of 10°C / min to 30°C / min, up to at least 1,200°C) or rapid firing conditions (e.g., heating rates of 60°C / min to 350°C / min, up to at least 1,200°C).

[0267] However, due to the use of nanoscale zirconia materials, the temperature required to obtain fully sintered products is typically no more than 1,350°C, and sometimes no more than 1,300°C.

[0268] Therefore, the dental restorations described in this text can be produced more economically because sintering requires less heat.

[0269] If necessary, an additional extraction step can be performed.

[0270] Such an extraction step can help remove or exchange ions from the product, such as sulfate ions that may be present at some stage of the process.

[0271] For example, pre-sintered products can be immersed in an alkaline solution, such as an aqueous solution of ammonium hydroxide.

[0272] After soaking, remove the pre-sintered product from the solution and wash it thoroughly with water. The product can be soaked in water for any desired period of time, such as at least 30 minutes, at least 1 hour, at least 2 hours, or at least 4 hours. If necessary, the soaking can be repeated several times by replacing the water with fresh water.

[0273] After soaking, the articles are typically dried in an oven to remove water. For example, the articles can be dried by heating in an oven at a temperature set to at least 80°C, at least 90°C, or at least 100°C. For example, the temperature can be maintained for at least 30 minutes, at least 60 minutes, or at least 120 minutes in the range of 80°C to 150°C, 90°C to 150°C, or 90°C to 125°C.

[0274] Ion exchange steps can typically be characterized by the following characteristics, either alone or in combination: duration: 5 to 24 hours; medium: aqueous ammonium hydroxide solution (e.g., 1N concentration); and / or temperature: 20°C to 25°C.

[0275] The present invention also relates to a zirconia ceramic dental restoration, particularly a monolithic zirconia ceramic dental restoration, which may be obtained from or can be obtained from a custom zirconia gel product.

[0276] Similar to custom-made zirconia gel products, zirconia ceramic dental restorations are typically available in the form of crowns, bridges, inlays, high inlays, or facets.

[0277] That is, the dental restoration has a shape that allows it to be used by a dentist without further adjustment or modification. In particular, no additional glazing and / or milling steps are required.

[0278] Anterior teeth have an outer surface or labial surface. The outer surface of anterior teeth corresponds to the outer surface of a veneer.

[0279] Dental restorations (such as veneers) also have an inner surface that corresponds to the outer surface of the prepared tooth in the labial direction.

[0280] Accordingly, the zirconia ceramic dental restorations described in this text include an outer surface area and an inner surface area.

[0281] The outer surface of the outer surface region or the inner surface of the inner surface region, or both of these surfaces, may contain segments with shapes based on information associated with the patient's dental condition.

[0282] Both the outer and inner surface regions contain ceramic components and stabilizing components.

[0283] In addition, at least one partition of the inner surface region contains a coloring component or a stable component of different concentrations.

[0284] If necessary, at least one partition of the outer surface area may also contain a coloring component or a stable component of varying concentrations.

[0285] Typically, in at least one section of the inner surface area of ​​a zirconia ceramic dental restoration, the material in the inner surface area is less translucent than in the outer surface area. This arrangement has been found to more closely mimic the natural tooth structure, which has a relatively opaque dentin core and a relatively translucent enamel layer covering it.

[0286] In one respect, in up to three separate sections of the inner surface area, the material of the inner surface area of ​​the zirconia ceramic dental restoration is less translucent than the material of the outer surface area.

[0287] Therefore, it is not necessary to color the entire material of the inner surface area. Coloring of the material in the inner surface area is usually done only in those desired sections.

[0288] If necessary, differences in light transmission can be measured or analyzed using a microscope on the cross-section of the corresponding area of ​​the zirconia ceramic dental restoration.

[0289] If necessary, transmittance can also be evaluated by comparing the corresponding contrast reflectance (CR-R), as further outlined in the Examples section.

[0290] Contrast ratio is related to light transmission. It is the ratio of the brightness observed when measuring a test article of a specified thickness against a black background to when measuring the same article against a white background. Articles with high light transmittance will show varying brightness depending on the background, while articles with low light transmittance will show less variation.

[0291] The inner and outer surface regions come into contact with each other at an interface or transition region, which is typically non-planar.

[0292] Therefore, there exists an interface region or transition zone in which the material composition of the inner surface region and the outer surface region overlaps with each other.

[0293] This transition zone can be advantageous because it allows for a smoother transition between the two material compositions of the inner and outer surface regions.

[0294] The interface range and material composition can be modified and adjusted depending on the radiation curing conditions and / or the sequence of steps and / or the viscosity of the sol used.

[0295] The content of coloring components in the interface region or transition region is usually lower than that in the inner surface region.

[0296] If necessary, the difference in the content of the coloring component can be determined on samples cut from zirconia ceramic dental restorations for analysis using XRF technology.

[0297] The inner and / or outer surface areas typically have a thickness ranging from 0.02 mm to 3 mm or from 0.05 mm to 2 mm.

[0298] Zirconia ceramic dental restorations consist of ceramic components, stabilizing components, and coloring components.

[0299] The main ceramic component is zirconium oxide. In addition to zirconium oxide, hafnium oxide is usually present, but in smaller quantities.

[0300] Alumina is usually absent and / or unintentionally added.

[0301] Possible crystalline phase stabilizing components include oxides of Ce, Mg, Ca, La, and Y, with the use of Y sometimes being preferred.

[0302] The crystalline phase-stabilizing component calculated as an oxide is typically present in the following amounts: at least 1 mol%, 2 mol%, or 3 mol%; at most 7 mol%, 6 mol%, or 5 mol%; from 1 mol% to 7 mol%, or from 2 mol% to 6 mol%, or from 3 mol% to 5 mol%; mol% is relative to zirconia ceramic dental restorations.

[0303] Coloring components present in zirconia ceramic dental restorations include oxides selected from Fe, Mn, Er, Pr, Tb, Cr, Co, Mo, Nb and mixtures thereof, wherein combinations of Fe, Mn, Er and Pr are sometimes preferred.

[0304] Zirconia ceramic dental restorations may contain or consist essentially of the following components: 70 mol% to 98 mol% of ZrO2; 0 mol% to 2 mol% of HfO2; 2 mol% to 7 mol% of Y2O3; Coloring components in amounts from 0.001 mol% to 1 mol% are selected from oxides of Fe, Mn, Er, Pr, Tb, Cr, Co, Mo, Nb, or mixtures thereof. Mole% is relative to zirconia ceramic dental restorations.

[0305] According to another embodiment, the material of the zirconia ceramic dental restoration may contain or consist substantially of the following components: 90 mol% to 98 mol% of ZrO2, 0 mol% to 2 mol% of HfO2, 3 mol% to 6 mol% of Y2O3, Coloring components in amounts from 0.01 mol% to 0.8 mol% are selected from oxides of Fe, Mn, Er, Pr, Tb, Cr, Co, Mo, Nb, or mixtures thereof. Mole% is relative to zirconia ceramic dental restorations.

[0306] It has been found that higher Y₂O₃ content typically leads to an increase in the cubic phase in zirconia ceramics after sintering to the final density. Higher cubic phase content may result in better translucency.

[0307] Zirconia ceramic dental restorations typically have a tetragonal phase content of at least 40 vol%, at least 45 vol%, or at least 50 vol%.

[0308] High tetragonal phase content is usually associated with high material strength.

[0309] Surprisingly, it has been found that the nanoscale zirconia materials described in this text can have a fairly high tetragonal phase content during their sintering stage, even though the material has a fairly high content of stable components (e.g., more than 4 mol%, 5 mol%, or 6 mol% relative to zirconia ceramic dental restorations).

[0310] In addition, for materials with a stable component content ranging from 3 mol% to 5.0 mol%, the average particle size of the zirconia ceramic dental restoration is 80 nm to 300 nm; or for materials with a stable component content ranging from 5.1 mol% to 8 mol%, the average particle size is 150 nm to 550 nm; mol% is relative to the zirconia ceramic dental restoration.

[0311] Zirconia ceramic dental restorations are made from very fine granular materials because they are produced by processing compositions containing nanoscale components.

[0312] Due to the method described in this text, the grain size of the zirconia ceramic body is significantly smaller than that of the zirconia material with the same stabilizer content but made by pressing the corresponding powder and sintering the compact at a higher temperature.

[0313] Zirconia materials with this average grain size have been found to have favorable optical properties, particularly regarding transmittance.

[0314] In addition, if desired, zirconia ceramic dental restorations can be characterized by the following features, either individually or in combination: a) Porosity: less than 0.1% by volume; b) Thickness between the outer and inner surfaces: 0.5 mm to 0.02 mm in at least one section of the monolithic zirconia ceramic dental restoration; c) Translucency: When measured on a 1 mm thick sample using light in the wavelength range of 360 nm to 780 nm, at least 40% in at least one section of a monolithic zirconia ceramic dental restoration; d) Opalescence: Measured at least 9 on a sample with a thickness of 1 mm; e) Contrast: In two sections of a monolithic zirconia ceramic dental restoration normalized to 1 mm thickness and spaced 3 mm apart, the difference between them is at least 5%.

[0315] The following combinations of features are sometimes preferred: b) and c); c) and d); d) and e); c), d) and e). If desired, these properties can be determined as described in the Examples section.

[0316] Materials with a porosity of less than 0.1% by volume or less than 0.05% by volume are considered dense.

[0317] The zirconia ceramic dental restorations and related methods described herein enable or allow the manufacture of ceramic articles with very thin segments. It has been found that dental restorations with such thin, mesh-like structures cannot be produced by other means, such as milling or 3D printing.

[0318] A segment should be understood as a distinguishable volume, and it typically corresponds to an anatomical feature on the tooth (i.e., a dental condition). The incisal tubercle is an example. The three incisal tubercle features typically extend across the width of the tooth, thus they are visible features ranging in size from tens to hundreds of micrometers. When observed by a dentally trained eye without additional magnification, the segment is visually distinguishable.

[0319] A segment of a zirconia ceramic dental restoration should generally be understood as having a dimension of at least 100µm, 150µm, or 200µm in one, two, or three dimensions.

[0320] Zirconia ceramic dental restorations with such thin sections cannot be effectively produced by milling.

[0321] Zirconia ceramic dental restorations are highly translucent in at least one section of the restoration (e.g., the occlusal area or the incisal edge area).

[0322] It was also found that the opalescence of the dental restoration material was in a zone that essentially corresponded to the opalescence of natural teeth.

[0323] Furthermore, the manufacturing method described in this text allows for the production of custom zirconia ceramic dental restorations, in which the contrast of different sections of the restoration may vary at small distances.

[0324] The methods described herein generally do not require the following steps, alone or in combination: a zirconia powder pressing step; a milling step; a step of applying a coloring liquid; and / or a step of applying an enamel layer.

[0325] Therefore, there is no need to perform the step of pressing powder (especially zirconia powder) to obtain dental milling blocks that are subsequently machined.

[0326] Since dental restorations are provided through a casting process, there is no need for a milling step, i.e., the step of machining dental milling blocks in a milling machine.

[0327] Since zirconia ceramic dental restorations already contain coloring components, there is no need to apply coloring liquid later.

[0328] Because of the presence of a translucent outer surface area, there is no need to apply a glaze layer to the zirconia ceramic dental restoration.

[0329] The following provides additional embodiments or aspects related to the custom zirconia gel products, dental restorations and methods described in this text.

[0330] Implementation Plan 1

[0331] A method for producing dental restorations, the method comprising, substantially comprising, or comprising the following steps: (a) Place a curable sol S1 of amount A1 in a mold with a non-planar inner bottom surface. (b) Place a curable sol S2 of amount A2 into contact with curable sol S1. (c) Optionally, the quantity is A N Curable sol S N Place it in contact with sol S1 and / or sol S2, where N = 1, 2, 3, 4...10; (d) Optionally, in sol S2 and / or optional sol S N Apply a second mold to the top. (e) Perform a radiation curing step to obtain a zirconia gel product. (f) Optionally, a post-curing step may be performed (e.g., by heating the zirconia gel article to a temperature in the range of 35°C to 80°C, or by photocuring), particularly for the purpose of improving the stability of the zirconia gel article. (g) Optionally, the zirconia gel product is soaked in another liquid (e.g., diethylene glycol ethyl ether or ethanol), particularly for liquid exchange. (h) Preferably, the zirconia gel product is converted into a zirconia aerogel product by applying a supercritical drying step, particularly for the purpose of removing liquid. (i) The zirconia aerogel product is heat-treated to a temperature in the range of 400°C to 800°C, particularly for the purpose of removing residual organic components from the zirconia aerogel product. (j) The three-dimensional product from the previous step is heated to a temperature in the range of 800°C to 1,050°C, particularly for the purpose of obtaining a pre-sintered product. (k) An extraction step may be optionally performed, particularly for the purpose of removing ions from the pre-sintered product. (l) Sintering the pre-sintered product to obtain a sintered zirconia ceramic product. Sol S1, Sol S2 and optional Sol S N Each contains Crystalline zirconium oxide particles, Crystal phase stabilizer components, Radiation can cure organic components. Photoinitiator, Liquid, and At least one of the sols contains a coloring component. The crystal phase stabilizer component is contained within the crystalline zirconia particles, and if a coloring component is present, the coloring component may be contained within the crystalline zirconia particles or exist as a separate component in the sol. The viscosity of each sol is 50 Pa at 23°C. s to 3,000 mPa Within the range of s; and Sol S1, sol S2, and optional sol S N They differ from each other, individually or in combination, in the following properties: The content of coloring components, The content of crystalline phase stable components, Content of crystalline zirconium oxide particles.

[0332] Implementation Plan 2

[0333] A dental restoration, particularly one obtainable by the methods described herein, is characterized by the following properties: The thickness between the outer and inner surfaces in at least one section is 0.5 mm to 0.02 mm. The optical properties of at least two segments differ regarding color and / or translucency: DE > 2 and / or %CR > 2, measured on a 1 mm thick sample with individual coloring. Opalescence: at least 10, ZrO2 content: 90 mol% to 98 mol% HfO2 content: 0 mol% to 2 mol% Y2O3 content: 3 mol% to 6.5 mol%. Al2O3 content: 0 mol% to 0.1 mol%. The percentage (mol%) is relative to the dental ceramic zirconia product in question.

[0334] Implementation Plan 3

[0335] A custom-made zirconia gel product with the shape of a dental prosthesis. The customized zirconia gel product includes at least three regions: The inner surface region containing gel G1, Includes the outer surface region of gel G2, and Contains transition gel G 1 / 2 The transition area The material composition of the gel includes each of the following: Crystalline zirconium oxide particles, Crystal phase stabilizer components, Solidified organic components, Optional photoinitiator, Liquid, and At least one of the gels contains a color component. The phase stabilizer component is contained within the crystalline zirconia particles, and if a coloring component is present, the coloring component may be contained within the crystalline zirconia particles or exist as a separate component in the gel. Gel G1 is different from Gel G2. The transition region described therein has a color gradient, and The transition gel comprises a mixture of materials consisting of gels G1 and G2.

[0336] The components, elements, or features mentioned in these embodiments correspond to the components, elements, or features described in this text.

[0337] The entire disclosure of all patents, patent documents, and publications cited herein is incorporated by reference as if each were individually incorporated. Various modifications and alterations to this invention will be apparent to those skilled in the art without departing from the scope and spirit of the invention. The foregoing description, examples, and data provide a description of the manufacture and use of the compositions of the invention and the methods of the invention. The invention is not limited to the embodiments disclosed herein. Those skilled in the art will understand that many alternative embodiments of the invention can be derived without departing from the spirit and scope of the invention.

[0338] Example

[0339] The objectives and advantages of this disclosure are further illustrated by the following embodiments. The specific materials and quantities, as well as other conditions and details cited in these embodiments, should not be construed as undue limitation of this disclosure.

[0340] Unless otherwise stated, all parts and percentages are by weight, all water is deionized water, and all molecular weights are weight-average molecular weights. Furthermore, unless otherwise stated, all experiments were conducted under ambient conditions (23°C; 10¹³ mbar).

[0341] method

[0342] Crystallization structure and size methods (XRD analysis)

[0343] Dry zirconia samples were hand-ground using an agate mortar and pestle. A large amount of sample was applied to a glass microscope slide to which a section of double-sided adhesive tape had been adhered using a scraper. The sample was pressed into the adhesive tape by forcing it against the tape with the scraper blade. Excess sample was removed by scraping the sample area with the edge of the scraper blade, leaving a thin layer of particles adhering to the adhesive. Any remaining loose material was removed by forcefully striking the hard surface of the microscope slide. Corundum (Linde 1.0µm alumina polishing powder, lot number C062, Union Carbide, Indianapolis, IN) was prepared in a similar manner and used for instrument broadening calibration of the X-ray diffractometer.

[0344] X-ray diffraction patterns were obtained using a Philips vertical diffractometer with a reflective geometry and copper K. a Radiation and scattered radiation were recorded using proportional detectors. The diffractometer was equipped with a variable incident beam slit, a fixed diffraction beam slit, and a graphite diffraction beam monochromator. Full-spectrum scans were recorded from 25° to 55° 2θ(2q) using steps of 0.04° and a dwell time of 8 seconds. An X-ray generator of 45 kV and 35 mA was used. Data for corundum standards were collected in three independent regions on several separate corundum stages. Similarly, data were collected in three independent regions on a thin-layer sample stage.

[0345] The observed diffraction peaks were identified by comparison with reference diffraction patterns contained in the International Data Center for Diffraction (ICDD) Powder Diffraction Database (Collection 1-47, ICDD, Newton Square, PA, USA). The diffraction peaks of the samples were attributed to either the cubic / tetragonal (C / T) or monoclinic (M) form of zirconia. For zirconia-based particles, the (111) peak of the cubic phase and the (101) peak of the tetragonal phase could not be separated, and therefore these phases were reported together. The amount of each zirconia form was evaluated on a relative basis, and the zirconia form with the strongest diffraction peak was designated as a relative intensity value of 100. The strongest lines of the remaining crystalline zirconia forms were scaled relative to this strongest line and given values ​​between 1 and 100.

[0346] The peak width of the diffraction maxima observed due to corundum was measured by peak fitting. The relationship between the average corundum peak width and the corundum peak position (2q) was determined by fitting a polynomial to these data to produce a continuous function for evaluating the instrument width at any peak position within the corundum testing range. The peak width of the diffraction maxima observed due to zirconia was measured by peak fitting of the observed diffraction peaks. The following peak widths were evaluated based on the presence of the zirconia phase: Cubic / square (C / T): (1 1 1) Monoclinic (M): (-1 1 1) and (1 1 1) Using K a1 and K a2 All measurements were performed using the Pearson VII peak shape model for the wavelength components and the linear background model. Peak widths were calculated as full width at half maximum (FWHM) in degrees. Peak fitting was performed using the capabilities of the JADE diffraction software suite. Peak widths were evaluated for three independent datasets obtained for the same thin-layer sample stage.

[0347] The sample peaks were corrected for instrument broadening by interpolating the instrument width values ​​from the corundum instrument calibration, and the corrected peak widths were converted to radians. The primary crystal size was calculated using the Scherrer formula.

[0348]

[0349] In the Scherrer formula, K is the shape factor (0.9 here), l is the wavelength (1.540598 Å), b is the peak width (in radians) calculated after correction for instrument broadening, and q is equal to half the peak position (scattering angle). b equals [calculated peak FWHM - instrument width] (converted to radians), where FWHM is the full width at half maximum. The cubic / tetragonal (C / T) average crystallite size is measured as the average of three measurements using the (1 1 1) peak. That is,

[0350] Photon Correlation Spectroscopy (PCS) Method

[0351] Particle size measurements were performed using a light scattering particle size analyzer equipped with a red laser with a wavelength of 633 nm (trade name "ZETASIZER-Nano Series, Model ZEN3600", available from Malvern Instruments Inc., Westborough, MA). Each sample was analyzed in a 1 square centimeter polystyrene sample cuvette. Approximately 1 gram of deionized water was filled into the sample cuvette, followed by the addition of a few drops (approximately 0.1 gram) of zirconia-based sol. The composition in each sample cuvette was mixed by aspirating the composition (e.g., the sample) into a clean pipette and then returning the composition to the sample cuvette several times. The sample cuvettes were then placed in the instrument and equilibrated at 25°C. The instrument parameters were set as follows: dispersant refractive index 1.330, dispersant viscosity 0.8872 MPa-s, material refractive index 2.10, and material absorbance 0.10 units. An automated dimensional measurement program was then run. The instrument automatically adjusts the laser beam position and attenuator settings to obtain optimal particle size measurement.

[0352] The light scattering particle size analyzer illuminates a sample with a laser and analyzes the intensity fluctuations of light scattered from the particles at a 173-degree angle. The instrument uses photon correlation spectroscopy (PCS) to calculate particle size. PCS uses the fluctuating light intensity to measure the Brownian motion of particles in a liquid. The particle size is then calculated as the diameter of a sphere moving at the measured velocity.

[0353] The intensity of light scattered by a particle is proportional to the sixth power of the particle size. The Z-mean size, or cumulative average, is the average value calculated from the intensity distribution, based on the assumption that the particles are unimodal, monodisperse, and spherical. The correlation function calculated from fluctuating light intensity is the intensity distribution and its average value. The average value of the intensity distribution is calculated based on the assumption that the particles are spherical. The Z-mean size and the average value of the intensity distribution are more sensitive to larger particles than to smaller particles.

[0354] The volume distribution gives the percentage of the total particle volume corresponding to particles within a given size range. The volume-mean size is the particle size corresponding to the average of the volume distribution. Because the particle volume is proportional to the cube of its diameter, this distribution is less sensitive to larger particles than the Z-mean size. Therefore, the volume-mean size is typically a smaller value than the Z-mean size.

[0355] Methods for measuring oxide content

[0356] The oxide content was measured using a thermogravimetric analyzer (trade name "TGA Q500", available from TA Instruments, New Castle, DE, USA). The sample (approximately 50 mg) was loaded into the TGA and heated to 900°C in air. The oxide content of the sample was equal to its residual weight after heating to 900°C.

[0357] Methods for measuring Archimedes density

[0358] The density of the sintered material was measured using the Archimedes technique. Measurements were performed on a precision balance (marked "XSE204," from Mettler-Toledo, LLC, Columbus, OH, USA) using a density measuring accessory (marked "Density measuring accessory for the XP / XS analytical balance," from Mettler-Toledo, LLC, Columbus, OH, USA). The sample was first weighed in air (A), then immersed in water and weighed (B). The water was distilled and deionized. Three drops of wetting agent (trade name "PERVITRO 75%," from Mettler-Toledo, LLC, Columbus, OH, USA) were added to 250 ml of water. The density was calculated using the balance's density function, using the formula... Where ρ0 is the density of water and ρ L It is the density of air (0.0012 g / cm³). 3 Relative density can be obtained from the theoretical density (ρ) of the reference material. t To calculate, .

[0359] Methods for measuring contrast reflectance (CR-R) and DE

[0360] CR-R values ​​represent opacity using a contrast method, and _E represents color difference. Recordings were performed using a Color i7 spectrophotometer (X-Rite Corp.) with a d / 8° optical configuration and D65 calibrated illumination, recording a spectral range between 360 nm and 750 nm with 10 nm wavelength intervals. A reflectance mode with a 10 mm aperture was used for this measurement. Color evaluation was configured with a 10° viewing angle, excluding specular reflections and including UV illumination. Fully sintered ceramic specimens approximately 1 mm thick were used for these measurements. Samples were measured using both light-colored and dark-colored backings. L was automatically calculated from the spectrum using X-Rite software. a and b The CR-R value is calculated automatically by the software, using a formula based on the ratio of dark backing to light backing. CR-R is expressed as a percentage. The higher the CR-R level, the less transparent the material, and the lower the CR-R level, the more translucent the material.

[0361] The color difference between sample 1 and sample 2 is calculated using the following formula:

[0362] Viscosity

[0363] Viscosity can be measured using the capillary viscometry method if needed. The fluid is placed in a cylinder with a diameter D of 10 mm, and a piston moves at a constant speed v of 2.9 mm / min, thus extruding the sol through a die with a length L of 38.1 mm and a diameter d of 0.58 mm. The force F that causes the piston to move at a constant speed is measured; this force is calibrated to piston friction. These measurements are performed using standard equipment such as Zwick, Ulm.

[0364]

[0365] pH value

[0366] If necessary, the pH value can be determined as follows: Disperse 1.0 g of the component in 10 ml of deionized water and stir for about 5 min. Immerse a calibrated pH electrode in the suspension and measure the pH value while stirring.

[0367] Elemental composition

[0368] If desired, elemental composition can be determined by X-ray fluorescence spectrometry (XRF), for example using the ZSX Primus II (from Rigaku, Japan). This method is particularly suitable for analyzing solids, such as zirconia ceramics or glass materials.

[0369] Opal

[0370] The product is considered to have opalescence if the calculated opalescence value OP meets the following conditions:

[0371] Among them (CIEa) T - CIEa R ) is the red-green coordinate a The difference between the transmission mode and the reflection mode, and (CIEb T - CIEb R (b) is the yellow-blue color coordinate. The difference between the transmission mode and the reflection mode.

[0372] The OP value can be determined using a Color i7800 integrating sphere benchtop spectrophotometer (x-rite, Michigan USA) with a sample 1.0 mm in height and 15 mm in diameter, applying the formula above.

[0373] Average grain size

[0374] The average grain size can be determined using the planar intercept procedure according to ASTM E112. The average grain size is the average of the grain sizes of 10 measurement lines. The average grain size of a measurement line is the length of the line in the SEM image divided by the number of grain boundary intercepts, and then multiplied by a shape factor of 1.56.

[0375] Porosity of zirconia products

[0376] The porosity of zirconia products can be determined by measuring the water absorption rate after immersing the product in water. The water absorption rate is the weight of the immersed product divided by the weight of the dried product. The pore volume is calculated from the water absorption at the measurement temperature and the density of water.

[0377]

[0378] Sol preparation

[0379] As described in WO 2016 / 191534 A1 (Examples Section - Processing: Preparation of Sol-S1), zirconia-based sols, Sol-I(a)-Soluble-III(a), are prepared, differing only in the feed composition. Yttrium acetate, ferric acetate, and erbium acetate are added to the precursor solution in appropriate amounts. The target composition of Sol-I(a)-Soluble-III(a) is listed in Table 1 below.

[0380]

[0381] Further processing of sol-I(a) to sol-II(a) increases its concentration and / or removes acetic acid (AcOH). One or a combination of ultrafiltration, dialysis, and distillation is used. A dialysis membrane (Membra-Cel) is employed. ™ Percolation and ultrafiltration were performed using an MD77 14x100 CLR filter. Distillation was carried out using rotary evaporation.

[0382] Sol-I(b)-sol-III(b) based on diethylene glycol monoethyl ether was prepared from sol-I(a)-sol-III(a) by adding 2-[2-(2-methoxyethoxy)ethoxy]acetic acid (MEEAA) (3.3 wt% relative to the number of oxides in the sol) and an appropriate amount of diethylene glycol monoethyl ether (adjusted to the desired final oxide concentration of 53 wt% in the sol), and concentrating each sol by rotary evaporation. 282 g of sol-I(b), 135 g of sol-II(b), and 70 g of sol-III(b) were obtained.

[0383] Preparation of casting sol

[0384] Relative to the weight of solid zirconium oxide in each sol (sol I(b), sol II(b), sol III(b)), 9.8% by weight of acrylic acid, 5% HEAA and 0.2% by weight of Irgacure 819 were added and stirred for 1 hour.

[0385] Casting sol CSol2 was obtained from sol II (b), and casting sol CSol3 was obtained from sol III (b).

[0386] To prepare a sol that provides a bright color to the incisal edge, 36.5 g of sol-I(b), 3.2 g of sol-II(b), and 0.24 g of sol-III(b) were partially mixed and stirred for 5 min to obtain a casting sol CSol1. The viscosity was determined to be 570 mPa using capillary viscometry. s.

[0387] Segmented casting method

[0388] To cast segmented objects from ceramic sol, the following procedure is used. The main body of the external tooth shape is created using CAD / CAM milling based on scanned data (.stl) of the anterior teeth. The mold dimensions need to be scaled according to the shrinkage factor throughout the process. The shrinkage factor is experimentally determined by measuring the dimensions of the cast body (e.g., 2.4 cm) and the final sintered body (e.g., 1.3 cm). The shrinkage factor is also calculated from the solids content of the casting sol. BIOSTAR is used. ™ VII device (Scheu, Germany) and COPYPLAST ® The mold material is formed using a vacuum thermoforming process. Avoid light exposure: Perform the procedure in a UV-filtered chamber (yellow light), or under low-light conditions when UV filtering is unavailable.

[0389] Small amounts of sol can be manually dispensed at room temperature using a pipette or a metering robot (Vieweg, VR3203).

[0390] If needed, a second mold can be placed on top of the cast sol to provide a second, customized external shape. The shape of the mold can be based on information associated with the patient's dental condition.

[0391] Curing was accomplished by applying UV light (Osram Dulux S Blue 9W / 71, Germany) for 15 seconds to 3 minutes. After curing, the gel sample was immediately removed from the mold and immersed in diethylene glycol monoethyl ether.

[0392] Supercritical fluid extraction method

[0393] The cast gel is dried by supercritical fluid extraction, for example, as described in the supercritical extraction method for gels in the Examples section of WO 2016 / 191534 A1 (Mayr et al.).

[0394] Burn-out and pre-sintering methods

[0395] The dried gel was placed on a bed of zirconia beads in an alumina crucible. The crucible was covered with an alumina plate and then fired in air according to the following procedure: 1-Heat from 20°C to 170°C at a rate of 18°C / hour. 2- Heating from 220°C to 244°C at a rate of 1°C / hour. 3-Heat from 244°C to 400°C at a rate of 6°C / hour. 4- Heating from 400°C to 1,000°C at a rate of 60°C / hour. 5. Maintain a temperature of 1000℃ for 1 hour. 6- Cool from 1,000°C to 20°C at a rate of 120°C / hour.

[0396] Ion exchange methods

[0397] The pre-sintered body was placed in a glass jar containing 1.0N NH4OH to a depth of approximately 2.5 cm and soaked for at least 16 hours. The NH4OH was then poured out, and the jar was filled with distilled water. The body was soaked in the distilled water for 1 hour. The water was then replaced with fresh distilled water. This process was repeated until the pH of the soaking water was equal to that of the fresh distilled water. The body was then dried at 90°C–125°C for at least 15 minutes.

[0398] Sintering method

[0399] The pre-sintered ion exchanger is placed in a furnace and sintered in air according to the following scheme: 1- Heating from 25℃ to 400℃ at a rate of 5.7℃ / s. 2- Heating from 400℃ to 1255℃ at a rate of 0.4℃ / s. 3. Maintain at 1,255°C for 800 seconds. 4-Cooled from 1,245°C to 700°C at a rate of -1.2°C / s.

[0400] 5. Remove from the oven and allow to cool naturally to room temperature.

[0401] Example

[0402] All samples were cast using molds with a maximum length of 2.3 cm and a maximum width of 1.8 cm. All samples were dried using a supercritical fluid extraction method and subsequently treated using burn-off and pre-sintering methods, ion exchange methods, and sintering methods to form fully dense ceramic products.

[0403]

[0404] Example 1

[0405] Example 1 demonstrates a prototype panel first cast with approximately 1.07 ml of casting sol CSol1. Then, three drops (approximately 0.02 ml, 0.06 ml, and 0.25 ml) of CSol3 were carefully cast onto the top of the CSol1, resulting in color difference between the regions. At the interface, the sol intrinsically mixed due to self-diffusion. Subsequently, photocuring was performed (approximately 3 min). After this process, the body had dimensions of a maximum length of 13 mm, a width of 9.5 mm, and a maximum thickness of 2 mm, and a weight of 0.74 g. The color difference between the regions was measured to be DE = 26 by a reference. Using XRD, 77% tetragonal microcrystalline phase and 23% cubic microcrystalline phase were determined. Using SEM, the grain size in the CSol1 partitions was measured to be 214 nm. Images of the prototype panel are shown below. Figure 1 As shown.

[0406] The sol-casting process of the prototype facet is schematically shown in Figure 2 (1) to (4) Figure 2 (1) through (4) show a mold with a custom concave inner surface. Inside the mold, CSo1 is present at the bottom (1), and small volumes of CSo1 2 are applied to different areas on top of CSo1 (2), (3). A transition region (4) is also shown formed by the diffusion and / or mixing of CSo1 and CSo2.

[0407] Example 2 (Ex 2)

[0408] Example 2 demonstrates a prototype panel where approximately 0.31 ml of casting sol Csol1 was first cast on the right edge of the mold, approximately 0.22 ml of casting sol Csol3 was cast on the left edge, and approximately 0.7 ml of Csol2 was cast on the main body, resulting in color differences between the three areas. At the interfaces, the sols internally mix due to self-diffusion. Photocuring was then performed (approximately 2 minutes). After this process, the main body had dimensions of a maximum length of 13 mm, a width of 9.5 mm, and a maximum thickness of 2 mm, with a weight of 0.66 g. The color difference between the areas, measured using a reference, was DE. 1,2 = 26、DE 2,3 = 34 and DE 1,3 =31. XRD was used to determine that 77% tetragonal and 23% cubic microcrystalline phases were present. SEM was used to determine the grain size of the Csol3 partition to be 300 nm. Images of the prototype veneer are shown below. Figure 3 As shown.

[0409] The sol-casting process of the prototype facet is schematically shown in Figure 4 (1) to (4) Figure 4 A mold with a custom concave inner surface is shown. Csol 1 (1) is present at the bottom of the mold. Different volumes of Csol 2 (2) and Csol 3 (3) are placed on top of or in contact with Csol 1. A transition region (4) is also shown formed by diffusion and / or mixing of Csol 1 with Csol 2 and Csol 3, respectively.

[0410] Example 3 (Ex 3)

[0411] Example 3 demonstrates a prototype insert cast into a first mold, wherein approximately 0.57 g of casting sol Csol1 was first cast, followed by approximately 0.71 g of Csol2 on the top side. A second mold was placed to form a second defined surface. Photocuring was performed (approximately 2 min). The second mold was removed, and subsequently, the insert was removed from the first mold. After this process, the body had a maximum thickness of 1.4 mm. The color difference between the regions, measured by a reference, was DE. 1,2 = 26. A photograph of the sample is shown below. Figure 5 As shown.

[0412] The sol-casting process of the prototype facet is schematically shown in Figure 6 (1) to (5) Figure 6A mold with a custom concave inner surface is shown. Inside the mold, Csol 1 is present at the bottom (1), and Csol 2 is placed on top of Csol 1 (2). A second mold with a convex outer surface is placed on top of Csol 2 (3), causing the two sols to mix in the transition area. After curing (4), a custom gel article with the shape of a dental prosthesis is obtained (5).

[0413] Comparative Example 1 (CE1)

[0414] CE1 is made by 3M Lava ™ The aesthetic fluorescent full-profile zirconia disc (3M Oral Care) is milled and the facets are finalized according to the manufacturer's instructions for use. For this material, the supplier reports an average grain size of approximately 1 µm. The facets are not glazed.

[0415] Although the material of the disc has a built-in chromaticity gradient, the appearance of the milled and sintered facet of CE1 is quite uniform in color compared to the inventive embodiments described above.

[0416] The image of the sample is as follows Figure 7 As shown

[0417] Comparative Example 2 (CE2)

[0418] CE2 is a 3D-printed panel made of zirconia nanosol, which is essentially a sol without coloring components, corresponding to Sol-I(a). The panel has a uniform appearance in terms of color. An Aiga Max 43 UV unit was used as the 3D printer.

[0419] The image of the sample is as follows Figure 8 As shown.

Claims

1. A custom-made zirconia gel product with the shape of a dental prosthesis, The custom zirconia gel product includes a transition region containing a transition gel, the transition region having a color gradient. The material composition of the transition gel includes Crystalline zirconium oxide particles, Crystal phase stabilizer components, Solidified organic components, Optional photoinitiator, Liquid, and Coloring components, The phase stabilizer component is contained in the crystalline zirconia particles, and the coloring component may be contained in the crystalline zirconia particles or exist as a separate component in the gel.

2. The custom zirconia gel article according to any one of the preceding claims, wherein the transition region is non-planar.

3. The custom zirconia gel article according to the preceding claim, wherein the custom zirconia gel article comprises at least three regions: an inner surface region containing gel G1, an outer surface region containing gel G2, and a transition gel G... 1 / 2 The aforementioned transition region, The geometry of the inner surface, outer surface, or both, and the inner and outer surfaces of the corresponding regions, based on information associated with the patient's dental condition.

4. The custom zirconia gel article according to the preceding claim, wherein the content of the coloring component in the transition region is lower than the content of the coloring component in the inner surface region.

5. A method for producing a custom zirconia gel article according to any one of claims 1 to 4, the method comprising the following steps: (a) Place a curable sol S1 of amount A1 in a mold with a non-planar inner bottom surface. (b) Place a curable sol S2 of amount A2 into contact with curable sol S1. (c) Optionally, the quantity is A N Curable sol S N Place them in contact with sol S1 and / or sol S2, where N = 1, 2, 3, 4... (d) Perform the curing step. Sol S1, Sol S2 and optional Sol S N Each contains Crystalline zirconium oxide particles, Crystal phase stabilizer components, Can solidify organic components, Photoinitiator, Optional coloring components, and liquid, At least sol S2 contains coloring components. The crystal phase stabilizer component is contained within the crystalline zirconia particles, and if a coloring component is present, the coloring component is contained within the crystalline zirconia particles or exists as a separate component in the sol. The viscosity of each sol, as measured according to the instructions, is 50 mPa at 23°C. s to 3,000 mPa Within the range of s; and Sol S1, sol S2, and optional sol S N They differ from each other individually or in combination in the following properties: the content of coloring components, the content of phase-stabilizing components, and the content of crystalline zirconia particles.

6. The method according to claim 5, wherein the non-planar inner bottom surface of the mold includes a section having a concave region and / or a convex region.

7. The method according to any one of claims 5 to 6, wherein the non-planar bottom surface of the mold includes segments having a geometry based on information associated with the patient's dental condition.

8. The method according to any one of claims 5 to 7, wherein the method further comprises the following step prior to step (a): Sols are available with varying amounts of stabilizing and / or coloring components. Mix at least two of these sols to obtain curable sol S1, curable sol S2, and optionally curable sol S N .

9. The method according to any one of claims 5 to 8, wherein the curable sol S1, the curable sol S2, and optionally the curable sol S3 are adjusted. N The chemical composition is matched with information associated with the patient's dental condition.

10. The method according to any one of claims 5 to 9, wherein the quantities A1 and A2 are different in volume.

11. The method according to any one of claims 5 to 10, wherein the sol is placed by any one of the following methods: casting; inkjet printing; or gradient printing using trench polymerization.

12. The method according to any one of claims 5 to 11, wherein the method does not include the following steps, individually or in combination: Powder pressing step; Milling step; The steps of applying coloring liquid; and / or applying glaze.

13. A dental prosthesis, said dental prosthesis being obtained by or capable of being obtained by the method according to any one of claims 5 to 12, said method further comprising the following steps: Extraction steps can be performed optionally, and Perform one or more heat treatment steps.

14. In particular, the dental restoration according to the preceding claim, the dental restoration having an outer surface region and an inner surface region, Zirconia ceramic dental restorations contain stabilizing components and coloring components. The inner surface region contains, in at least one partition of the inner surface region, a material with a higher contrast than the material of the outer surface region. The material of the zirconia ceramic dental restoration has At least 40% by volume tetragonal phase content, and The following average grain size For materials with a stable component content ranging from 3 mol% to 5.0 mol%, 80 nm to 300 nm, For materials with a stable component content ranging from 5.1 mol% to 8 mol%, 150 nm to 550 nm, Volume % and mole % are relative to the dental restoration, wherein the average grain size is determined according to ASTM E112 and according to the instructions.

15. The dental restoration according to any one of claims 13 to 14, wherein the dental restoration comprises at least one segment with a thickness in the range of 0.5 mm to 0.02 mm.

Images