CN118267302B - Dental cast porcelain and preparation method thereof - Google Patents

Abstract

The invention discloses a preparation method of cast porcelain for dentistry, which comprises the steps of selecting silicate glass and zirconia as basic materials, and respectively grinding the two basic materials to obtain silicate glass powder and zirconia powder with different particle sizes; according to the color and transparency requirements of the target teeth, setting a gradual change rule of layered mixing, and gradually changing the adding proportion of silicate glass powder and zirconia powder according to the gradual change rule in the mixing process to prepare layered mixed powder; filling the prepared layered mixed powder into a dental mold for pressing to form a preliminary cast porcelain material; through physical layer design, the microstructure of the cast porcelain material is effectively controlled, the natural gradual change effect of color and transparency is realized, the cast porcelain material with layered gradual change color attribute is provided, the appearance fidelity of the repair material is remarkably improved, the color transition of natural teeth can be more accurately simulated, and the adaptability and the aesthetic property of the cast porcelain material in the oral cavity are greatly improved.

Description

Dental cast porcelain and preparation method thereof

Technical Field

The present invention relates to the technical field of medical materials, and in particular to a dental cast porcelain and a preparation method thereof.

Background Art

In the field of contemporary dental restoration, the preparation technology of cast porcelain materials that pursue high performance and high aesthetics has become a research hotspot. With the improvement of people's requirements for oral health and aesthetics, traditional metal-based restorative materials are gradually replaced by non-metallic materials. Among them, cast porcelain has attracted widespread attention due to its good biocompatibility, excellent mechanical properties and aesthetic effects close to natural teeth. However, although the existing technology has made certain progress in simulating the color and transparency of natural teeth, it still faces many challenges in the material preparation process.

Existing dental casting ceramic material preparation technologies mainly focus on improving the corrosion resistance and mechanical properties of casting ceramic materials by adjusting chemical formulas or complex heat treatment processes; however, these methods often require the use of high-cost raw materials and equipment. On the one hand, the preparation cost is high, and on the other hand, the appearance realism is poor. It is difficult to accurately simulate the color transition and delicate texture of natural teeth (the color of conventional adult teeth is close to gradient color, and teeth are composed of a multi-layer structure, and different layers have different colors and transparencies). It is difficult to achieve the color gradient and transparency control effects of dentures. There is a significant color difference between dentures and real teeth, which affects the user experience.

In view of this, it is necessary to improve the preparation process of dental cast porcelain in the prior art to solve the technical problem of poor appearance realism.

Summary of the invention

The object of the present invention is to provide a dental cast porcelain and a preparation method thereof to solve the above technical problems.

To achieve this object, the present invention adopts the following technical solutions:

A method for preparing dental cast porcelain, comprising:

Silicate glass and zirconium oxide are selected as basic materials, and the two basic materials are ground respectively to obtain silicate glass powder and zirconium oxide powder with different particle sizes;

According to the color and transparency requirements of the target teeth, a gradient rule for layered mixing is formulated, and during the mixing process, the addition ratio of the silicate glass powder and the zirconium oxide powder is gradually changed according to the gradient rule to prepare a layered mixed powder;

The prepared layered mixed powder is filled into a dental mold, and each layer of the layered mixed powder is pressed together through a mechanical compaction process to form a preliminary ceramic casting material.

Optionally, the step of formulating a layered blending gradient rule according to the color and transparency requirements of the target teeth may specifically include:

Determine the color parameters of the target teeth by a chromatographic analysis instrument, evaluate the transparency and reflective properties of the teeth, and obtain the color and transparency requirements of the target teeth; the color parameters include hue, saturation and brightness;

According to the color and transparency requirements of the target tooth, analyzing and obtaining the gradual change characteristics of the target tooth from the crown to the root;

According to the gradient characteristics, a gradient rule of color and transparency is designed, wherein the gradient rule is to grade the color of the target tooth from light to dark and the transparency from high to low, so as to form a plurality of hierarchical sequences of color and transparency;

According to the gradient rule, the specific ratio of silicate glass powder to zirconium oxide powder corresponding to each hierarchical sequence is determined.

Optionally, during the mixing process, the addition ratio of the silicate glass powder and the zirconium oxide powder is gradually changed according to the gradual change rule to obtain a layered mixed powder; specifically comprising:

Formulate a layered mixing execution plan according to the specific proportion of each layer sequence, wherein the operation plan includes the mixing sequence, the specific proportion of each layer and the selection of the mixing technology;

According to the execution plan, silicate glass powder and zirconium oxide powder of corresponding proportions for each of the hierarchical sequences are prepared, and each powder is pre-treated; the pre-treatment includes impurity removal and particle classification.

Optionally, each powder is pretreated, and then further comprises:

According to the execution plan, each prepared silicate glass powder and zirconium oxide powder are mixed in layers to obtain a layered mixed powder; wherein, during the layered mixing process, the silicate glass powder and zirconium oxide powder of each layer sequence are added layer by layer, and each time a layer of powder is added, a corresponding mixing technology is used;

The prepared layered mixed powder is sampled, and the sampled layered mixed powder is tested for color consistency and evaluated for transparency, and the execution plan of the layered mixing is adjusted according to the evaluation results.

Optionally, the gradient rule includes five level sequences, and the five level sequences are respectively a crown tip transparent layer, a crown tip transparent layer, an intermediate transition layer, a root color layer and a root tip colored layer.

Optionally, the forming of the preliminary casting porcelain material further comprises:

The dental mold filled with the preliminary ceramic casting material is placed in a sintering furnace and heat treated by a staged heating and heat preservation method;

The heat-treated cast porcelain material is cooled and taken out, the cast porcelain material is surface treated, and a transparent protective layer is coated on the outside of the cast porcelain material to obtain a finished dental cast porcelain product.

Optionally, the heat treatment is performed in a stepwise heating and heat preservation manner, specifically including:

Determine the starting temperature of heat treatment according to the sintering requirements of the casting ceramic material; the initial temperature is set within the minimum temperature range required for sintering and impurity removal of the casting ceramic material;

Based on the starting temperature, a heating rate and heating stages in the heat treatment process are formulated; wherein the heating rate in each heating stage is adjusted according to the reaction characteristics of the ceramic casting material and the sintering target;

After reaching a preset critical temperature rise stage, the sintering furnace is maintained at a preset insulation temperature for a preset time period so that the internal structure of the casting ceramic material is uniformly transformed;

After reaching the preset final heating stage, the heat preservation time corresponding to the final heating stage is set to complete the sintering process.

Optionally, the heat-treated cast ceramic material is cooled and taken out, and the cast ceramic material is subjected to surface treatment, specifically comprising:

Cooling the ceramic casting material after the heat treatment, formulating a cooling curve for the cooling treatment, and using the cooling system of the sintering furnace to cool the ceramic casting material according to the cooling curve;

After the cast porcelain material is cooled to room temperature, it is taken out from the sintering furnace and subjected to appearance inspection for defects and dimensions;

The cast ceramic material that has passed the appearance inspection is mechanically ground and polished to remove rough spots on the surface of the cast ceramic material.

Optionally, the particle size range of the silicate glass powder and the zirconium oxide powder is set to 0.1-1 mm.

The present invention also provides a dental cast porcelain, which is prepared by the above-mentioned method for preparing the dental cast porcelain; the dental cast porcelain comprises:

A multi-layer gradient structure, wherein the color and transparency of the multi-layer gradient structure from the crown tip to the root are multi-layer gradient;

A composite substrate made of silicate glass powder and zirconium oxide powder in a predetermined ratio;

A transparent protective layer is coated on the outer surfaces of the multi-layer gradient structure and the composite material substrate.

Compared with the prior art, the present invention has the following beneficial effects: during processing, silicate glass and zirconium oxide are selected as basic materials, and are physically ground separately to obtain powders with different particle sizes; by adjusting the ratio of silicate glass powder to zirconium oxide powder, and mixing powders of different ratios in layers in the order of color depth and transparency, the mixed powder is filled into a special mold, and by slight mechanical compaction, each layer is ensured to be tightly combined, thereby enhancing the mechanical strength and light transmittance of the cast porcelain and forming a preliminary cast porcelain material; compared with the preparation process in the prior art, the present method effectively controls the microstructure of the cast porcelain material through physical hierarchical design, and realizes the natural gradient effect of color and transparency, providing a cast porcelain material with layered gradient color properties, significantly improving the appearance realism of the restorative material, and being able to more accurately simulate the color transition and delicate texture of natural teeth, greatly improving its adaptability and aesthetics in the oral cavity.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

The structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with this technology. They are not used to limit the conditions under which the present invention can be implemented, and therefore have no substantive technical significance. Any structural modification, change in proportion or adjustment of size, without affecting the effects and purposes that can be achieved by the present invention, should still fall within the scope of the technical contents disclosed by the present invention.

FIG1 is a schematic diagram of a process flow of a method for preparing dental cast porcelain according to the first embodiment of the present invention;

FIG2 is a second schematic flow diagram of the method for preparing dental cast porcelain according to the first embodiment of the present invention;

FIG. 3 is a third schematic flow chart of the method for preparing dental cast porcelain according to the first embodiment of the present invention.

DETAILED DESCRIPTION

In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

In the description of the present invention, it should be understood that the terms "upper", "lower", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. It should be noted that when a component is considered to be "connected" to another component, it may be directly connected to the other component or there may be a centrally arranged component at the same time.

The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

Embodiment 1:

1 to 3 , an embodiment of the present invention provides a method for preparing dental cast porcelain, comprising:

S1, selecting silicate glass and zirconium oxide as base materials, and grinding the two base materials respectively to obtain silicate glass powder and zirconium oxide powder with different particle sizes;

Selecting silicate glass and zirconia as basic materials and grinding them to obtain powders of different particle sizes is the basis and prerequisite for the preparation of casting porcelain materials. The key to this process is to adjust the particle size of the powder through physical grinding to meet different light transmittance and strength requirements. Powders of different particle sizes can affect the material's densification, sintering behavior, and the aesthetics and mechanical properties of the final product.

Optionally, the particle size range of silicate glass powder and zirconium oxide powder is set to 0.1~1mm. The selection of particle size range (0.1~1mm) provides flexibility for material design, so that the powder particle size can be adjusted according to the requirements of the final casting porcelain, and the performance and appearance of the casting porcelain can be optimized. Smaller particle size helps to improve the transparency and fineness of the casting porcelain, while larger particle size is more conducive to improving the strength and crack resistance of the casting porcelain. By finely adjusting the particle size distribution within this range, the overall performance of the casting porcelain can be optimized according to different application requirements and design goals, and high-quality dental restoration effects can be achieved.

S2, according to the color and transparency requirements of the target teeth, a gradient rule for layered mixing is formulated. During the mixing process, the addition ratio of silicate glass powder and zirconium oxide powder is gradually changed according to the gradient rule to prepare a layered mixed powder;

According to the color and transparency requirements of the target teeth, a set of layered mixing gradient rules are designed, and the addition ratio of silicate glass powder and zirconium oxide powder is gradually adjusted during the mixing process. This is the key to achieving a natural gradient in the color and transparency of the cast porcelain. This layered mixing method allows for fine control of the color depth and light transmittance of the cast porcelain material during the preparation process, thereby simulating the color gradient and transparency characteristics of natural teeth. This step embodies the combination of material science and design, achieving the established aesthetic goals through precise adjustment of the material ratio to meet the needs of highly personalized dental restorations.

S3, filling the prepared layered mixed powder into a dental mold, and pressing each layer of the layered mixed powder through a mechanical compaction process to form a preliminary ceramic casting material.

The prepared layered mixed powder is loaded into a dental mold, and each layer of powder is tightly combined through a mechanical compaction process to form a preliminary casting porcelain material. This is the transformation process from raw material to preform. This step ensures that the powder is evenly distributed in the mold, increases the density of the material through mechanical compaction, and lays a solid foundation for the subsequent sintering process.

The working principle of the present invention is as follows: during processing, silicate glass and zirconium oxide are selected as basic materials, and are physically ground separately to obtain powders with different particle sizes. By adjusting the ratio of silicate glass powder to zirconium oxide powder, and mixing powders of different ratios in layers in the order of color depth and transparency, the mixed powder is filled into a special mold, and through slight mechanical compaction, each layer is ensured to be tightly combined, thereby enhancing the mechanical strength and light transmittance of the cast porcelain and forming a preliminary cast porcelain material. Compared with the preparation process in the prior art, the present method effectively controls the microstructure of the cast porcelain material through physical hierarchical design, and realizes the natural gradient effect of color and transparency, providing a cast porcelain material with layered gradient color properties, which significantly improves the appearance realism of the restorative material, can more accurately simulate the color transition and delicate texture of natural teeth, and greatly improves its adaptability and aesthetics in the oral cavity.

In this embodiment, it is specifically described that step S2 specifically includes:

S21, measuring the color parameters of the target teeth by a chromatographic analysis instrument, evaluating the transparency and reflective properties of the teeth, so as to obtain the color and transparency requirements of the target teeth; the color parameters include hue, saturation and brightness;

The determination of color parameters and transparency evaluation of target teeth by chromatographic analysis instruments is the starting point for achieving personalized and highly simulated effects in the entire preparation process; by obtaining color parameters such as hue, saturation, and value, as well as the transparency and reflective properties of teeth, the natural color and light transmittance of target teeth can be accurately understood and recorded. The precise execution of this step provides a scientific basis for the subsequent material ratio and layer design, ensuring that the casting porcelain material can simulate the color and transparency of natural teeth as much as possible to meet the needs of personalized restoration.

S22, according to the color and transparency requirements of the target tooth, analyzing and obtaining the gradual change characteristics of the target tooth from the crown to the root;

Based on the color and transparency data obtained in step S21, analyzing the color and transparency gradient characteristics of the target tooth from the crown to the root is a key step in achieving the natural beauty of cast porcelain; by analyzing the natural gradient characteristics of the target tooth, we can better understand the law of color and transparency changes of natural teeth, and lay the foundation for designing gradient rules that conform to the characteristics of natural teeth. This step ensures that the prepared cast porcelain material can be closer to natural teeth in terms of visual and optical properties, and improves the naturalness and aesthetics of the restoration material.

S23, designing a gradient rule of color and transparency according to the gradient characteristics, wherein the gradient rule is to grade the color of the target tooth from light to dark and the transparency from high to low, so as to form a plurality of hierarchical sequences of color and transparency;

This graded and sequenced design approach ensures that the material can accurately simulate the color and transparency gradient of natural teeth throughout the preparation process.

S24, determining the specific ratio of silicate glass powder to zirconium oxide powder corresponding to each hierarchical sequence according to a gradient rule.

Through precise material ratios, the color depth and transparency of the casting porcelain material at different levels can be controlled to achieve a natural gradient effect from the crown to the root; through fine-tuning the ratio of silicate glass and zirconium oxide, the complex color and transparency characteristics of natural teeth can be simulated at the microscopic level, providing a reliable guarantee for the preparation of high-quality dental restoration materials.

It is further explained that the gradient rule includes five level sequences, and the five level sequences are the crown tip transparent layer, the crown tip transparent layer, the middle transition layer, the root color layer and the root tip colored layer.

Crown tip transparent layer: This layer is located at the crown tip of the outermost layer of the tooth, and is characterized by the highest transparency and the lightest color.

Crown bright white layer: Immediately following the transparent layer at the crown tip is the crown bright white layer. The transparency of this layer is slightly lower than that of the transparent layer at the crown tip, and its color is mainly bright white.

Intermediate transition layer: located between the bright white layer and the root color layer, serving as a bridge for the transition of color and transparency; this layer is characterized by the color and transparency beginning to transition to a more natural tooth tone, gradually increasing the color depth and reducing the transparency to achieve a smooth visual transition.

Root color layer: The area close to the root of the tooth, the color is darker than the middle transition layer and the transparency is further reduced.

Apical pigmented layer: Located in the innermost layer, it has the darkest color and the lowest transparency. This layer simulates the color characteristics of the root tip of the tooth. It is usually more concentrated and deep in color and has the lowest transparency, providing depth and three-dimensionality to the entire tooth.

In this embodiment, it is further explained that after step S24, the following steps are further included:

S25, formulate an execution plan for layered mixing according to the specific proportion of each layer sequence, the operation plan includes the mixing sequence, the specific proportion of each layer and the selection of mixing technology;

The mixing order, the specific ratio of each layer and the choice of mixing technology directly affect the uniformity of the layered mixed powder and the color and transparency of the final casting porcelain material. Through the designed operation plan, it can be ensured that each layer of material is accurately mixed according to the established gradient rules, providing operational guarantees for achieving the color gradient and transparency effects of natural teeth.

S26, according to the execution plan, prepare silicate glass powder and zirconium oxide powder in corresponding proportions for each hierarchical sequence, and pre-treat each powder; the pre-treatment includes impurity removal and particle classification.

This step ensures the quality of the mixed powder and removes impurities and particles of non-compliant particle size that may affect the sintering quality and the aesthetics of the final cast porcelain; the pretreated powder has better fluidity and mixing properties, which helps to improve the uniformity and accuracy of the layered mixing process.

In this embodiment, it is further explained that after step S26, the following steps are further included:

S27, mixing each prepared silicate glass powder and zirconium oxide powder in layers according to the execution plan to prepare layered mixed powder; wherein, during the layered mixing process, the silicate glass powder and zirconium oxide powder of each layer sequence are added layer by layer, and each time a layer of powder is added, a corresponding mixing technology is used;

By precisely adding and mixing silicate glass powder and zirconium oxide powder layer by layer, it is ensured that each layer can reflect the color and transparency characteristics of the design. The mixing technology used is extremely critical to achieving uniform distribution of powder, which affects the quality of the layered mixed powder and the gradient effect of the final product.

S28, sampling the prepared layered mixed powder, and performing a color consistency test and a transparency evaluation on the sampled layered mixed powder, and adjusting the layered mixing execution plan according to the evaluation results.

By evaluating the layered mixed powder, problems with the mixing ratio or technology can be discovered in a timely manner, providing data support for further optimizing the execution plan of the layered mixing. This dynamic adjustment and optimization mechanism ensures that the final casting porcelain material can be as close to the design goal as possible, achieving a highly natural and beautiful restoration effect.

In this embodiment, it is further explained that after step S3, the following steps are further included:

S4, placing the dental mold filled with the preliminary casting ceramic material into a sintering furnace, and performing heat treatment by means of staged heating and heat preservation;

First, pre-sintering is performed at a relatively low temperature to remove organic components and moisture from the material, and then the temperature is gradually increased to the complete sintering temperature to achieve material densification and strength enhancement. During the sintering process, the microstructure and light transmittance of the cast porcelain are adjusted by precisely controlling the temperature and holding time.

S5, cooling and taking out the heat-treated casting porcelain material, performing surface treatment on the casting porcelain material, and coating the casting porcelain material with a transparent protective layer to obtain a finished dental casting porcelain product.

After sintering, the cast porcelain material is taken out after cooling, and mechanical grinding and polishing are used to remove tiny surface defects, increase its glossiness and comfort in the mouth. If necessary, a transparent protective layer is applied to further improve its wear resistance and long-term stability.

In this embodiment, it is specifically described that step S4 specifically includes:

S41, placing the dental mold filled with preliminary casting ceramic material into the sintering furnace; the correct execution of this process is the basis for ensuring that the casting ceramic material can be evenly heated and sintered.

S42, determining the starting temperature of the heat treatment according to the sintering requirements of the ceramic casting material; the initial temperature is set within the minimum temperature range required for sintering and impurity removal of the ceramic casting material;

The setting of the starting temperature takes into account the removal of impurities and moisture in the casting ceramic material, and avoids introducing an excessively fast heating rate that may cause stress or cracks inside the material. Precise control of this step helps lay a stable foundation for the subsequent sintering process of the casting ceramic material.

S43, based on the starting temperature, the heating rate and heating stage in the heat treatment process are formulated; wherein the heating rate in each heating stage is adjusted according to the reaction characteristics of the casting porcelain material and the sintering target; for example, a slower heating rate is adopted in the initial stage to ensure sufficient removal of organic matter, and when approaching the final sintering temperature, the heating rate can be appropriately increased to promote the densification of the material.

Formulating the heating rate and heating stage during the heat treatment process is the key to achieving fine sintering control. By adjusting the rate of each heating stage according to the characteristics of the casting ceramic material and the sintering target, the densification process and structural development of the material can be optimized to avoid sintering defects. This staged heating strategy allows the material to reach the sintering temperature in a more controlled and balanced manner, which helps to improve the quality and consistency of the finished product.

S44, after reaching a preset critical temperature rise stage, maintaining the sintering furnace at a preset insulation temperature for a preset time, so that the internal structure of the casting porcelain material is uniformly transformed;

Insulation after the preset critical heating stage is an important step to ensure that the internal structure and chemical reaction of the casting ceramic material are fully carried out. The setting of the insulation stage allows the sintering reaction inside the material to be completed at a stable temperature, which promotes the uniform transformation and densification of the material structure, and is beneficial to improving the physical properties and appearance of the casting ceramic material.

S45, after reaching the preset final heating stage, the heat preservation time corresponding to the final heating stage is set to complete the sintering process.

Precise control of the final heating stage is important for optimizing the mechanical properties and transparency of the cast ceramic material, and also affects the color and gradient effect of the material.

In this embodiment, it is specifically described that step S5 specifically includes:

S51, cooling the heat-treated ceramic casting material, formulating a cooling curve for the cooling treatment, and using a cooling system of the sintering furnace to cool the ceramic casting material according to the cooling curve;

By developing and following a precise cooling curve, the temperature of the cast porcelain material can be controlled to drop evenly, avoiding damage to the material caused by thermal stress. The cooling system of the sintering furnace can accurately adjust the cooling rate to ensure the structural stability and performance consistency of the cast porcelain material; this step directly affects the internal quality of the finished cast porcelain product and its long-term reliability.

S52, after the cast porcelain material is cooled to room temperature, it is taken out from the sintering furnace and visually inspected for defects and dimensions;

Through this step, possible defective products can be discovered and eliminated in time, such as casting porcelain materials with cracks, deformation or sizes that do not meet the requirements, to ensure that only products that meet the standards enter the subsequent processing and handling process. This preliminary quality screening plays an important role in maintaining the quality standards of finished products.

S53, mechanically grinding and polishing the casting ceramic material that has passed the appearance inspection to remove rough spots on the surface of the casting ceramic material.

Removing rough spots on the surface not only improves the surface accuracy of the casting ceramic material, but this step requires delicate operation to ensure that the surface of the casting ceramic material is not damaged or its shape and size are changed, while achieving the desired smooth and glossy effect.

S54, coating a transparent protective layer on the outside of the casting porcelain material to obtain a finished dental casting porcelain product. Coating a transparent protective layer on the outside of the casting porcelain material is an important means to enhance the performance of the finished product and extend its service life. The transparent protective layer can not only improve the wear resistance and chemical corrosion resistance of the casting porcelain material, but also maintain its beautiful transparency and glossiness. Selecting a suitable coating material and uniform coating technology is the key to ensuring the performance of the protective layer.

Embodiment 2:

The present invention also provides a dental cast porcelain, which is prepared by the preparation method of the dental cast porcelain in Example 1; the dental cast porcelain comprises:

A multi-layer gradient structure, wherein the color and transparency of the multi-layer gradient from the crown tip to the root are multi-layer gradients; wherein the multi-layer gradient structure sequentially includes a crown tip transparent layer, a crown bright white layer, an intermediate transition layer, a root color layer and a root tip colored layer; ensuring that the cast porcelain can visually simulate the delicate transitions and diverse color levels of natural teeth.

The composite material substrate is made of silicate glass powder and zirconium oxide powder in a preset ratio; the two materials are mixed in a specific ratio and layer to form a composite substrate that can change the transparency and color depth layer by layer.

A transparent protective layer is coated on the outer surface of the multi-layer gradient structure and the composite material substrate. The protective layer provides additional wear resistance and chemical corrosion resistance, while maintaining the beautiful transparency and gloss of the cast porcelain, thereby extending the service life of the dental cast porcelain.

The dental cast porcelain in this embodiment is formed by a carefully designed multi-layer gradient structure, a composite substrate of silicate glass and zirconium oxide, and an optimized heat treatment and surface fine treatment process, which ultimately forms a dental cast porcelain with both high simulation and excellent physical and chemical properties. The coated transparent protective layer provides long-term protection for the cast porcelain, making its application in the oral cavity more reliable and durable.

As described above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims (3)

1. A method for preparing cast porcelain for dentistry, which is characterized by comprising the following steps:

Silicate glass and zirconia are selected as base materials, and the two base materials are respectively ground to obtain silicate glass powder and zirconia powder with different particle sizes;

according to the color and transparency requirements of the target teeth, setting a gradual change rule of layered mixing, and gradually changing the adding proportion of silicate glass powder and zirconia powder according to the gradual change rule in the mixing process to prepare layered mixed powder;

filling the prepared layered mixed powder into a dental mold, and pressing each layer of powder of the layered mixed powder through a mechanical compaction process to form a preliminary cast porcelain material;

Placing the dental mould filled with the primary casting porcelain material into a sintering furnace, and performing heat treatment in a sectional heating and heat preservation mode;

cooling and taking out the heat-treated cast porcelain material, carrying out surface treatment on the cast porcelain material, and coating a transparent protective layer outside the cast porcelain material to obtain a cast porcelain finished product for dentistry;

wherein, according to the color and transparency requirement of the target teeth, making a gradual change rule of layered mixing; the method specifically comprises the following steps:

measuring color parameters of the target teeth through a chromatographic analysis instrument, and evaluating transparency and reflection characteristics of the teeth to obtain the color and transparency requirements of the target teeth; the color parameters include hue, saturation, and brightness;

according to the color and transparency requirements of the target tooth, analyzing and obtaining the gradual change characteristic of the target tooth from the crown to the root;

According to the gradual change characteristics, designing a gradual change rule of color and transparency, wherein the gradual change rule is to grade the color of the target tooth from light to dark and the transparency from high to low, so as to form a plurality of hierarchical sequences about the color and the transparency; the gradual change rule comprises five layer sequences, wherein the five layer sequences are a crown tip transparent layer, a crown bright white layer, an intermediate transition layer, a root color layer and a root tip coloring layer respectively;

according to the gradual change rule, determining the specific proportion of silicate glass powder and zirconia powder corresponding to each layer sequence;

the adding proportion of the silicate glass powder and the zirconia powder is gradually changed according to the gradual change rule, and layered mixed powder is prepared; the method specifically comprises the following steps:

according to the specific proportion of each hierarchical sequence, a hierarchical mixing execution plan is formulated, wherein the operation plan comprises a mixing sequence, specific proportion of each layer and selection of a mixing technology;

According to the execution plan, preparing silicate glass powder and zirconia powder in corresponding proportion of each hierarchical sequence, and preprocessing each powder; the pretreatment comprises impurity removal and particle classification;

layering and mixing each prepared silicate glass powder and zirconia powder according to the execution plan to prepare layered mixed powder; in the layered mixing process, silicate glass powder and zirconia powder of each layer sequence are added layer by layer, and each layer of powder is added, and a corresponding mixing technology is adopted;

Sampling the prepared layered mixed powder, performing color consistency test and transparency evaluation on the sampled layered mixed powder, and adjusting the execution plan of layered mixing according to the evaluation result;

Wherein, adopt segmentation temperature rising and heat preservation mode to carry out the heat treatment, specifically include:

Determining the initial temperature of heat treatment according to the sintering requirement of the cast porcelain material; the initial temperature is set in the minimum temperature range required by sintering and impurity removal of the cast porcelain material;

based on the initial temperature, setting a heating rate and a heating stage in the heat treatment process; the heating rate of each heating stage is adjusted according to the reaction characteristics of the cast porcelain material and the sintering target;

after reaching a preset key heating stage, maintaining the sintering furnace at a preset heat preservation temperature for a preset period of time so as to uniformly transform the internal structure of the ceramic casting material;

After reaching a preset final heating stage, setting heat preservation time corresponding to the final heating stage, and completing the sintering process;

The method for surface treatment of the ceramic casting material comprises the steps of cooling the ceramic casting material after heat treatment, taking out the ceramic casting material, and carrying out surface treatment on the ceramic casting material, wherein the method specifically comprises the following steps:

cooling the ceramic casting material after heat treatment, making a cooling curve of the cooling treatment, and cooling the ceramic casting material according to the cooling curve by adopting a cooling system of the sintering furnace;

taking out the ceramic casting material from the sintering furnace after the ceramic casting material is cooled to room temperature, and carrying out appearance detection of defects and sizes;

and mechanically polishing and polishing the cast porcelain material with qualified appearance detection, and removing rough points on the surface of the cast porcelain material.

2. The method for producing a dental cast porcelain according to claim 1, wherein the particle size range of the silicate glass powder and the zirconia powder is set to 0.1 to 1mm.

3. A dental cast porcelain produced by the method of producing a dental cast porcelain according to any one of claims 1 to 2; the dental cast porcelain comprises:

a multi-layer graded structure having a multi-layer graded color and transparency from crown tip to root;

the composite material substrate is prepared from silicate glass powder and zirconia powder in a preset proportion;

And the transparent protective layer is coated on the outer surfaces of the multilayer gradual change structure and the composite material substrate.