阅读说明：本技术 仿生牙釉质氧化锆陶瓷材料块、牙修复体和制备方法 (Bionic tooth enamel zirconium oxide ceramic material block, tooth restoration body and preparation method ) 是由 孙玉春 周永胜 王勇 李洪文 李伟伟 陈虎 刘云松 张磊 翟文茹 于 2020-12-30 设计创作，主要内容包括：本公开涉及一种仿生牙釉质氧化锆陶瓷材料块、牙修复体和制备方法,包括：功能磨耗层,功能磨耗层包括氧化锆和用于稳定氧化锆的稳定剂,氧化锆由氧化锆纳米雏晶形成,纳米雏晶内形成有内晶缺陷,功能磨耗层外表面用于形成咬合面,功能磨耗层用于模拟天然牙齿釉质的直釉柱层。通过本公开的技术方案,能缓解牙修复体对于对颌牙过度磨损的情况,得到的氧化锆陶瓷材料块兼备了高强度、低硬度、低弹性模量的优点,降低了仿生牙釉质氧化锆陶瓷材料块和牙修复体的出现折断的概率,有利于延长牙修复体和对颌牙的使用寿命,另外,上述仿生牙釉质氧化锆陶瓷材料块的外观和牙修复体的外观均与天然牙齿的外观非常相似,具备优良的透光性、透明度和抛光度。(The invention relates to a bionic tooth enamel zirconium oxide ceramic material block, a tooth restoration and a preparation method, comprising the following steps: the functional wearing layer comprises zirconium oxide and a stabilizer for stabilizing the zirconium oxide, the zirconium oxide is formed by zirconium oxide nanocrystal, an inner crystal defect is formed in the nanocrystal, the outer surface of the functional wearing layer is used for forming an occlusal surface, and the functional wearing layer is used for simulating a straight glaze column layer of natural tooth enamel. By adopting the technical scheme, the condition that the dental restoration is excessively worn to the jaw teeth can be relieved, the obtained zirconia ceramic material block has the advantages of high strength, low hardness and low elastic modulus, the probability of breaking of the bionic enamel zirconia ceramic material block and the dental restoration is reduced, the service lives of the dental restoration and the jaw teeth are prolonged, in addition, the appearance of the bionic enamel zirconia ceramic material block and the appearance of the dental restoration are very similar to the appearance of natural teeth, and the dental restoration has excellent light transmittance, transparency and polishing degree.)

1. A piece of biomimetic enamel zirconia ceramic material, comprising:

the functional wearing layer comprises zirconium oxide and a stabilizer used for stabilizing the zirconium oxide, the zirconium oxide is formed by zirconium oxide nanocrystal, an inner crystal defect is formed in the nanocrystal, the outer surface of the functional wearing layer is used for forming an occlusal surface, and the functional wearing layer is used for simulating a straight glaze column layer of natural tooth enamel.

2. The piece of biomimetic enamel zirconia ceramic material according to claim 1, further comprising a stress buffer layer, wherein an inner surface of the functional wear layer is contiguous with an outer surface of the stress buffer layer, the stress buffer layer comprises stabilizer-stabilized zirconia, the zirconia of the stress buffer layer contains micro-nano-scale pores, and the stress buffer layer is used to simulate a hinge-glaze layer of the natural tooth enamel.

3. The piece of biomimetic enamel zirconia ceramic material according to claim 2, further comprising a fracture-resistant substrate layer, an inner surface of the stress buffer layer abutting the fracture-resistant substrate layer, the fracture-resistant substrate layer being made of stabilizer-stabilized zirconia, the fracture-resistant substrate layer being configured to support the stress buffer layer.

4. The piece of biomimetic enamel zirconia ceramic material according to claim 2 or 3,

the elastic modulus of the stress buffer layer in the area close to the fracture-resistant base layer is larger than that of the stress buffer layer in the area close to the functional wearing layer.

5. The piece of biomimetic enamel zirconia ceramic material according to claim 2 or 3,

the hardness of the stress buffer layer in the area close to the fracture-resistant substrate layer is higher than that of the stress buffer layer in the area close to the functional wearing layer.

6. A preparation method of a bionic tooth enamel zirconium oxide ceramic material block is characterized by comprising the following steps:

processing the zirconia nano-crystallites to obtain zirconia ceramic powder comprising a stabilizer;

pressing the zirconia ceramic powder by an isostatic pressing process to obtain a functional wearing layer for simulating a straight glaze pillar layer of natural tooth enamel.

7. The method for preparing a piece of biomimetic enamel zirconia ceramic material according to claim 6, further comprising:

pressing the zirconia ceramic powder by an isostatic pressing method to obtain a stress buffer layer with micro-nano pores, wherein the stress buffer layer is used for simulating a twisted glaze column layer of the natural tooth enamel;

and forming the stress buffer layer and the functional wearing layer into a non-homogeneous integrated structure, wherein the stress buffer layer can buffer the stress from the power consumption wearing layer.

8. The method for preparing a piece of biomimetic enamel zirconia ceramic material according to claim 6 or 7, further comprising:

pressing the zirconia ceramic powder by an isostatic pressing method to obtain a fracture-resistant substrate layer;

and forming the bending resistant substrate layer and the stress buffer layer into a heterogeneous integrated structure, wherein the bending resistant substrate layer can support the stress buffer layer.

9. A preparation method of a dental prosthesis of a bionic tooth enamel zirconium oxide ceramic material is characterized by comprising the following steps:

constructing a three-dimensional digital model of the dental prosthesis;

importing the three-dimensional digital model and the preset size of the three-dimensional digital model into a tool path planning program of numerical control cutting equipment;

controlling the data cutting equipment by the tool path planning program, and cutting the bionic dental enamel zirconium oxide ceramic material block according to any one of claims 1-5 according to the three-dimensional digital model to obtain the dental prosthesis of the bionic dental enamel zirconium oxide ceramic material.

10. A dental prosthesis of a bionic enamel zirconia ceramic material is characterized by comprising:

the dental restoration prepared by the method for preparing the bionic dental enamel zirconium oxide ceramic material according to claim 9.

Technical Field

The disclosure relates to the technical field of dental restorations, in particular to a bionic enamel zirconium oxide ceramic material block, a preparation method of the bionic enamel zirconium oxide ceramic material block, a preparation method of a dental restoration body made of a bionic enamel zirconium oxide ceramic material and a dental restoration body made of the bionic enamel zirconium oxide ceramic material.

Background

When people chew, the upper and lower teeth form a pair of special wearing pairs, namely tooth wearing pairs. Under the control of central nerve, taking mastication muscle as power and occlusal process as procedures, the chewing circulation is repeatedly carried out, and the complex chewing function is completed by 900 times per meal on average. The contact mode of the upper jaw teeth and the lower jaw teeth is mainly friction and collision, the corresponding wear types are abrasive wear and fatigue wear, and the two wear modes are alternately generated and mutually coupled and enhanced.

After a natural human tooth is lost, a denture is required for restoration, and a single-layer full-zirconia dental restoration is usually used as the denture.

In the prior art, although a single-layer full-zirconia dental restoration body is widely used, at least problems exist:

(1) the single-layer full-zirconia dental prosthesis has high hardness, and can cause excessive wear to the jaw teeth in the use process.

(2) The single-layer full-zirconia dental prosthesis has high density and rigidity, cannot relieve stress generated in the chewing process, and can possibly cause serious diseases such as jaw tooth trauma, occlusal trauma, temporomandibular joint disorder and the like.

(3) For the dental prosthesis of full-mouth single-layer full-zirconia, the dental prosthesis is easy to break after long-term use, and the long-term use effect is influenced.

It is to be noted that the information disclosed in the above background section is only for enhancement of understanding of the background of the present disclosure, and thus may include information that does not constitute prior art known to those of ordinary skill in the art.

Disclosure of Invention

The purpose of the disclosure is to provide a bionic tooth enamel zirconium oxide ceramic material block, a dental prosthesis and a preparation method, which overcome the problem of excessive wear of the jaw teeth caused by the dental prosthesis of single-layer full zirconium oxide in the related art at least to a certain extent.

Additional features and advantages of the disclosure will be set forth in the detailed description which follows, or in part will be obvious from the description, or may be learned by practice of the disclosure.

According to one aspect of the present disclosure, there is provided a piece of biomimetic enamel zirconia ceramic material comprising: the functional wearing layer comprises zirconium oxide and a stabilizer used for stabilizing the zirconium oxide, the zirconium oxide is formed by zirconium oxide nanocrystal, an inner crystal defect is formed in the nanocrystal, the outer surface of the functional wearing layer is used for forming an occlusal surface, and the functional wearing layer is used for simulating a straight glaze column layer of natural tooth enamel.

In one embodiment of the present disclosure, the dental enamel further comprises a stress buffer layer, wherein the inner surface of the functional wearing layer is adjacent to the outer surface of the stress buffer layer, the stress buffer layer comprises zirconia stabilized by a stabilizing agent, the zirconia of the stress buffer layer contains micro-nano-scale pores, and the stress buffer layer is used for simulating a twisted glaze column layer of the natural tooth enamel.

In one embodiment of the present disclosure, the zirconia of the functional wear layer is ordered and formed from the zirconia nanocrystal.

In one embodiment of the present disclosure, the stress buffer layer has a heterogeneous distribution of elastic modulus and hardness.

In one embodiment of the present disclosure, the stress buffer layer has a graded distribution of elastic modulus and hardness.

In one embodiment of the present disclosure, the bending-resistant substrate layer is further included, an inner surface of the stress buffer layer is adjacent to the bending-resistant substrate layer, the bending-resistant substrate layer is made of zirconia stabilized by a stabilizer, and the bending-resistant substrate layer is used for supporting the stress buffer layer.

In one embodiment of the present disclosure, the elastic modulus of the region of the stress buffer layer near the fracture-resistant base layer is greater than the elastic modulus of the region of the stress buffer layer near the functional wear layer.

In one embodiment of the present disclosure, a hardness of a region of the stress buffer layer adjacent to the fracture-resistant base layer is greater than a hardness of a region of the stress buffer layer adjacent to the functional wear layer.

In one embodiment of the present disclosure, the functional wear layer, the stress buffer layer, and the fracture-resistant substrate layer are heterogeneous, unitary structures formed by a curing process.

In one embodiment of the present disclosure, the stabilizer of the functional wear layer comprises one of cerium oxide, magnesium oxide, calcium oxide, yttrium oxide, strontium oxide, niobium oxide, ytterbium oxide, erbium oxide, and holmium oxide.

In one embodiment of the disclosure, the stabilizer of the functional wearing layer is 8 mol% to 12 mol% cerium oxide, or 8 mol% to 12 mol% magnesium oxide, or 8 mol% to 12 mol% calcium oxide, or 3 mol% to 5 mol% yttrium oxide, or 8 mol% to 12 mol% strontium oxide, or 8 mol% to 12 mol% niobium oxide.

In one embodiment of the present disclosure, the stabilizer of the stress buffer layer includes at least two of cerium oxide, magnesium oxide, calcium oxide, yttrium oxide, strontium oxide, niobium oxide, ytterbium oxide, erbium oxide, and holmium oxide.

In one embodiment of the disclosure, the stabilizer of the stress buffer layer is 8 mol% to 12 mol% of cerium oxide and 8 mol% to 12 mol% of magnesium oxide, or 8 mol% to 12 mol% of cerium oxide and 8 mol% to 12 mol% of calcium oxide, or 8 mol% to 12 mol% of cerium oxide and 3 mol% to 5 mol% of yttrium oxide, or 8 mol% to 12 mol% of magnesium oxide and 8 mol% to 12 mol% of calcium oxide, or 8 mol% to 12 mol% of magnesium oxide and 3 mol% to 5 mol% of yttrium oxide, or 8 mol% to 12 mol% of calcium oxide and 3 mol% to 5 mol% of yttrium oxide.

In one embodiment of the present disclosure, the stabilizer of the antiflex substrate layer includes 3 mol% to 5 mol% yttria.

According to another aspect of the present disclosure, there is provided a method for preparing a piece of biomimetic enamel zirconia ceramic material, comprising: processing the zirconia nano-crystallites to obtain zirconia ceramic powder comprising a stabilizer; pressing the zirconia ceramic powder by an isostatic pressing process to obtain a functional wearing layer for simulating a straight glaze pillar layer of natural tooth enamel.

In one embodiment of the present disclosure, the method for preparing the bionic enamel zirconia ceramic material block further comprises: pressing the zirconia ceramic powder by an isostatic pressing method to obtain a stress buffer layer with micro-nano pores, wherein the stress buffer layer is used for simulating a twisted glaze column layer of the natural tooth enamel; and forming the stress buffer layer and the functional wearing layer into a non-homogeneous integrated structure, wherein the stress buffer layer can buffer the stress from the power consumption wearing layer.

In one embodiment of the present disclosure, the method for preparing the bionic enamel zirconia ceramic material block further comprises: pressing the zirconia ceramic powder by an isostatic pressing method to obtain a fracture-resistant substrate layer; and forming the bending resistant substrate layer and the stress buffer layer into a heterogeneous integrated structure, wherein the bending resistant substrate layer can support the stress buffer layer.

According to still another aspect of the present disclosure, there is provided a method for preparing a dental restoration of a biomimetic enamel zirconia ceramic material, comprising: constructing a three-dimensional digital model of the dental prosthesis; importing the three-dimensional digital model and the preset size of the three-dimensional digital model into a tool path planning program of numerical control cutting equipment; and controlling the data cutting equipment through the tool path planning program, and cutting the bionic tooth enamel zirconium oxide ceramic material block according to the three-dimensional digital model to obtain the tooth restoration body made of the bionic tooth enamel zirconium oxide ceramic material.

In an embodiment of the present disclosure, the controlling the data cutting device by the tool path planning program to cut the bionic enamel zirconia ceramic material block according to the three-dimensional digital model to obtain the dental prosthesis of the bionic enamel zirconia ceramic material includes: acquiring a data model of the bionic enamel zirconium oxide ceramic material block to be cut; matching and aligning the three-dimensional digital model with the data model of the bionic tooth enamel zirconium oxide ceramic material block until the three-dimensional digital model is contained in the data model of the bionic tooth enamel zirconium oxide ceramic material block; generating cutting information according to the matching and aligning result, wherein the cutting information comprises at least one of cutting orientation, cutting angle and cutting distance; and the tool path planning program sends the cutting information to the data cutting equipment so that the data cutting equipment can cut the bionic enamel zirconium oxide ceramic material block to obtain the tooth restoration body model of the bionic enamel zirconium oxide ceramic material.

In an embodiment of the present disclosure, controlling the data cutting device by the tool path planning program to cut the bionic enamel zirconia ceramic material block according to the three-dimensional digital model, so as to obtain the dental prosthesis of the bionic enamel zirconia ceramic material further includes: and sintering and polishing the obtained dental prosthesis model of the bionic enamel zirconium oxide ceramic material to obtain the dental prosthesis of the bionic enamel zirconium oxide ceramic material.

According to still another aspect of the present disclosure, there is provided a dental restoration made of a bionic enamel zirconia ceramic material, which is prepared by the method for preparing a dental restoration made of a bionic enamel zirconia ceramic material according to any one of the above technical solutions.

In one embodiment of the present disclosure, the dental prosthesis of a biomimetic enamel zirconia ceramic material further comprises: the non-homogeneous integrated structure comprises a functional wearing layer, a stress buffer layer and an anti-bending base layer, wherein the functional wearing layer is used for simulating a straight glaze column layer of natural tooth enamel, the stress buffer layer is a micro-nano-grade hole and is used for simulating a twisted glaze column layer of the natural tooth enamel and buffering stress from the power consumption wearing layer, and the anti-bending base layer is used for supporting the stress buffer layer.

In one embodiment of the present disclosure, the thickness of the functional wear layer of the dental prosthesis ranges from 0.3mm to 0.6 mm.

In one embodiment of the present disclosure, the thickness of the stress buffering layer of the dental restoration ranges from 0.1mm to 0.2 mm.

In one embodiment of the present disclosure, the thickness of the fracture-resistant base layer of the dental prosthesis ranges from 0.5mm to 1 cm.

In one embodiment of the disclosure, the dental prosthesis has an overall thickness in the range of 1mm-2 cm.

According to the bionic dental enamel zirconium oxide ceramic material block, the dental prosthesis and the preparation scheme provided by the embodiment of the disclosure, the wear of the dental prosthesis on the jaw teeth can be effectively reduced by designing the zirconium oxide functional wear layer stabilized by the stabilizing agent, and the service life of the dental prosthesis and the service life of the jaw teeth can be prolonged.

Furthermore, by arranging the stress buffer layer with the micro-nano-grade hole, the stress of the functional wear layer can be effectively reduced, and the use experience of a user is improved.

Furthermore, the anti-folding base layer is arranged to support the stress buffer layer, so that the possibility of folding loss of the dental restoration body after long-term use can be effectively reduced, and the reliability of the dental restoration body can be further improved.

And finally, the dental restoration formed on the basis of the functional wearing layer, the stress buffer layer and the anti-bending base layer has the color very similar to the appearance color of natural teeth, has excellent light transmittance, transparency and polishing degree, and is favorable for further improving the use experience of users.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and together with the description, serve to explain the principles of the disclosure. It is to be understood that the drawings in the following description are merely exemplary of the disclosure, and that other drawings may be derived from those drawings by one of ordinary skill in the art without the exercise of inventive faculty.

FIG. 1 shows a schematic view of a piece of biomimetic enamel zirconia ceramic material in an embodiment of the present disclosure;

FIG. 2 illustrates a flow chart of a piece of biomimetic enamel zirconia ceramic material in an embodiment of the present disclosure;

FIG. 3 shows a flow chart of another method of making a piece of biomimetic enamel zirconia ceramic material in an embodiment of the present disclosure;

FIG. 4 shows a flow chart of another method of making a piece of biomimetic enamel zirconia ceramic material in an embodiment of the present disclosure;

FIG. 5 shows a flow chart of a method of manufacturing a dental restoration of a biomimetic enamel zirconia ceramic material mass according to an embodiment of the present disclosure;

FIG. 6 shows a flow chart of a method of making another method of making a dental restoration of biomimetic enamel zirconia ceramic material blocks in an embodiment of the present disclosure;

FIG. 7 shows a flow chart of a method for producing a dental restoration of a biomimetic enamel zirconia ceramic material block according to an embodiment of the present disclosure;

FIG. 8 shows a schematic view of a dental restoration of a biomimetic enamel zirconia ceramic material in an embodiment of the present disclosure;

fig. 9 shows an imaging schematic diagram of a stress buffer layer of a dental restoration made of a biomimetic enamel zirconia ceramic material under an optical microscope in an embodiment of the present disclosure;

fig. 10 shows an imaging schematic diagram of a stress buffer layer of a dental restoration made of a biomimetic enamel zirconia ceramic material in an embodiment of the present disclosure under an electron microscope.

Detailed Description

Example embodiments will now be described more fully with reference to the accompanying drawings. Example embodiments may, however, be embodied in many different forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

Furthermore, the drawings are merely schematic illustrations of the present disclosure and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and thus their repetitive description will be omitted. Some of the block diagrams shown in the figures are functional entities and do not necessarily correspond to physically or logically separate entities. These functional entities may be implemented in the form of software, or in one or more hardware modules or integrated circuits, or in different networks and/or processor devices and/or microcontroller devices.

According to the scheme provided by the disclosure, the wear of the dental prosthesis on the jaw teeth can be effectively reduced by designing the zirconium oxide functional wear layer stabilized by the stabilizing agent, and the service life of the dental prosthesis and the service life of the jaw teeth can be prolonged. Furthermore, by arranging the stress buffer layer with the micro-nano-grade hole, the stress of the functional wear layer can be effectively reduced, and the use experience of a user is improved. Furthermore, the anti-folding base layer is arranged to support the stress buffer layer, so that the possibility of folding loss of the dental restoration body after long-term use can be effectively reduced, and the reliability of the dental restoration body can be further improved. Finally, the dental restoration formed by the functional wearing layer, the stress buffer layer and the anti-bending base layer has the color close to that of natural teeth, and is beneficial to further improving the use experience of users.

In the bionic enamel zirconia ceramic material block, the dental restoration and the preparation scheme disclosed by the invention, the following key concepts are involved:

(1) the method for preparing the nano zirconia includes, but is not limited to, physical methods, gas phase chemical methods, wet chemical methods (liquid phase chemical methods, referred to as wet methods for short), and the like. The hydrothermal method is one of wet chemical methods, and means that in a special closed reaction container (high-pressure kettle), an aqueous solution is adopted as a reaction medium, and a high-temperature and high-pressure reaction environment is created by heating the reaction container, so that substances which are usually insoluble or insoluble are dissolved and recrystallized; water here acts as a solvent, mass transfer medium, reactant, etc.

The hydrothermal method preparation can be subdivided into hydrothermal crystallization, hydrothermal oxidation, hydrothermal decomposition, hydrothermal precipitation, hydrothermal-electric submerged arc and the like, and can be divided into two categories according to the principle: one is that the particle size is increased by hydrothermal method, such as hydrothermal crystallization; one is particle size reduction, such as hydrothermal oxidation, and the like.

The hydrothermal preparation of zirconia generally comprises the following steps:

(1.1) hydrothermal method for preparing powder directly from solution,

(1.2) the anhydrous, crystallized or amorphous powder can be obtained by adjusting the hydrothermal temperature.

(1.3) particle size can be controlled by hydrothermal temperature.

(1.4) controlling the shape and form of the powder by the starting material.

(1.5) the chemical composition and stoichiometry can be controlled.

(1.6) the prepared powder has high sintering activity.

(2) Isostatic compaction is a very important ceramic forming technology, and is a method for compressing and forming powder by transferring isotropic pressure through a fluid medium at normal temperature. Compared with the conventional forming technology, the isostatic pressing forming has the advantages that the density of the formed blank is high, the density of the blank is 5% -15% higher than that of the blank formed by common compression molding, and the blank is uniform in density, so that the isostatic pressing forming is suitable for products with large length-diameter ratio of columnar shape and barrel shape.

(3) The reference to the jaw is also to the static contact relationship between the upper and lower dentition. Occlusion refers to the dynamic contact between the upper and lower teeth.

(4) Stabilizer for zirconia: the tetragonal phase stabilized to room temperature is the precondition of stress-induced phase transition, the process is the key for obtaining excellent performance of the zirconia ceramic, and the zirconia stabilized by the stabilizing agent shows abnormally high fracture energy, so that the material shows abnormally high fracture toughness, and the phase transition toughening is generated, thereby obtaining high toughness and high wear resistance.

Hereinafter, the steps of the bionic enamel zirconia ceramic material block according to the present exemplary embodiment will be described in more detail with reference to the drawings and examples.

Fig. 1 shows a flow chart of a biomimetic enamel zirconia ceramic material block in an embodiment of the present disclosure.

As shown in fig. 1, a piece of biomimetic enamel zirconia ceramic material according to an embodiment of the present disclosure, comprises: a functional wearing layer 102, the functional wearing layer 102 comprising zirconia and a stabilizer for stabilizing the zirconia, the zirconia being formed of zirconia nanocrystallines in which an inner crystal defect is formed, the outer surface 1022 of the functional wearing layer 102 for forming an occlusal surface, the functional wearing layer 102 for simulating a straight enamel column layer of natural tooth enamel.

In the above embodiment, the functional wearing layer 102 is made of zirconia stabilized by a stabilizing agent to simulate a straight glaze column layer of natural tooth enamel, so that the density and rigidity of the functional wearing layer 102 are reduced, the wear of the dental prosthesis on the jaw teeth can be effectively reduced, the wear resistance of zirconia ceramics is weakened, the tribological performance matching of the zirconia ceramic dental prosthesis and the natural teeth of the human body is realized, and the service life of the dental prosthesis and the jaw teeth is prolonged. In addition, the color of the bionic tooth enamel zirconium oxide ceramic material block is very similar to the appearance color of a natural tooth, and the bionic tooth enamel zirconium oxide ceramic material block has excellent light transmittance, transparency and polishing degree.

In one embodiment of the present disclosure, the bionic tooth enamel zirconia ceramic material block further comprises a stress buffer layer 104, an inner surface 1024 of the functional wearing layer 102 is adjacent to an outer surface 1042 of the stress buffer layer 104, the stress buffer layer 104 comprises zirconia stabilized by a stabilizer, the zirconia of the stress buffer layer 104 contains micro-nano-scale pores, and the stress buffer layer 104 is used for simulating an enamel hinge column layer of the natural tooth enamel.

In the embodiment, the stress buffer layer 104 with the micro-nano-scale pores is arranged below the functional wear layer 102 to relieve the stress from the functional wear layer 102, the large strain energy caused by the occlusal force is absorbed by regulating and controlling the synergistic effect of the micro-nano-scale pores and the stress-induced phase change, the overhigh occlusal stress is dissipated and buffered, the long-term servo reliability of the bionic weakened full-zirconium crown prosthesis is ensured, the functional wear layer deforms along with the fracture and compression of the chewing process of a patient, the shape of the dental prosthesis better meets the chewing requirement, the hardness and the wear resistance of the dental prosthesis are reduced, the situations of jaw tooth trauma, occlusal trauma, temporomandibular joint disorder and the like are reduced, and the service life of jaw teeth and the dental prosthesis is favorably optimized.

For example, by adding alumina nanocrystals and strontium aluminate platelets to cerium stabilized tetragonal zirconia, and adding the local disorder degree of the tetragonal zirconia lattice, that is, by improving the entropy of configuration, the stability of tetragonal zirconia is further regulated, the fracture toughness of zirconia is greatly improved, the plasticity of the ceramic under the condition of far low yield stress is realized, and in addition, the loss of material strength is reduced as much as possible while the hardness and the elastic modulus are reduced.

The micro-nano pores of the stress buffer layer 104 may be in the shape of trabeculae, branches, other structures capable of realizing stress interruption, or a mixture of multiple structures.

In one embodiment of the present disclosure, the zirconia of the functional wear layer 102 is ordered and formed from the zirconia nanocrystal.

In the above embodiment, by adjusting and controlling the zirconia self-assembly mesomorphic microstructure and adjusting and controlling the sintering kinetics, the method of introducing an inner crystal defect structure into the zirconia nanocrystal to weaken the crystal grain strength, increasing the transgranular fracture ratio, and the like, achieves the balance of high strength, low hardness and low elastic modulus of the zirconia ceramic material.

The functional wear layer 102 may, for example, include a plurality of zirconia nanostructure layers of a specified thickness, which may be set in the range of 50 μm to 150 μm, but is not limited thereto.

In one embodiment of the present disclosure, the stress buffer layer 104 has a heterogeneous distribution of elastic modulus and hardness.

In the above embodiment, by arranging that the elastic modulus and the hardness of the stress buffer layer 104 are distributed in a heterogeneous manner, the stress on the stress buffer layer 104 is distributed in a dispersed manner and in multiple directions, which is beneficial to reducing the destructiveness of the stress on the overall structure of the stress buffer layer 104 and reducing the possibility of breakage or fracture of the stress buffer layer 104.

In one embodiment of the present disclosure, the elastic modulus and hardness of the stress buffer layer 104 are distributed in a stepwise progression.

In the above embodiment, by providing the elastic modulus and the hardness of the stress buffer layer 104 in a hierarchical progressive distribution, the magnitude of the stress applied to the stress buffer layer 104 also changes in a hierarchical manner, and the stress direction is decomposed into a plurality of directions, which is also beneficial to reducing the destructiveness of the stress to the overall structure of the stress buffer layer 104, and reducing the possibility of breakage or fracture of the stress buffer layer 104.

The progressive distribution of the elastic modulus and the hardness is not limited to the hierarchical distribution of the internal structure of the stress buffer layer 104, and the structure layer of the stress buffer layer 104 is usually micro-nano and the contact between the layers is dense, so that the layered structure of the stress buffer layer 104 cannot be observed in an electron microscope image.

In one embodiment of the present disclosure, the bionic enamel zirconia ceramic material block further includes a bending-resistant substrate layer 106, the inner surface 1044 of the stress buffer layer 104 is adjacent to the bending-resistant substrate layer 106, the bending-resistant substrate layer 106 is made of zirconia stabilized by a stabilizer, and the bending-resistant substrate layer 106 is used for supporting the stress buffer layer.

In the above embodiment, the fracture-resistant substrate layer 106 is prepared by arranging the zirconia stabilized by the stabilizer, so that the dental prosthesis and the implant substrate are better integrated, and the stress buffer layer 104 is supported, thereby reducing the probability of fracture of the dental prosthesis on the premise of ensuring the reliable structures of the functional wearing layer 102 and the stress buffer layer 104.

In which structural defects are reduced by adjusting the preparation parameters of the fracture-resistant substrate layer 106, the self-assembled zirconia crystals may be subject to further agglomeration, coalescence and sliding, for example, when the additively manufactured zirconia green body is exposed to rapid sintering under strong electromagnetic radiation, resulting in rapid densification without extensive diffusion processes, counteracting grain growth at the initial sintering stage, and thereby improving the strength, toughness and transparency of the zirconia ceramic.

The structural defects of the fracture-resistant substrate layer 106 may be reduced, for example, by adjusting a sintering temperature, the sintering temperature of the fracture-resistant substrate layer 106 being greater than or equal to 1300 degrees celsius, and the sintering time being less than or equal to 2 minutes.

In one embodiment of the present disclosure, the elastic modulus of the stress buffer layer 104 in the region near the fracture-resistant substrate layer 106 is greater than the elastic modulus of the stress buffer layer 104 in the region near the functional wear layer 102.

In one embodiment of the present disclosure, the hardness of the region of the stress buffer layer 104 proximate to the fracture-resistant substrate layer 106 is greater than the hardness of the region of the stress buffer layer 104 proximate to the functional wear layer 102.

In the above embodiment, the surface occlusion stress of the stress buffer layer 104 can be buffered by setting the elastic modulus of the inner layer of the stress buffer layer 104 to be larger than the elastic modulus of the outer layer of the stress buffer layer, and the higher the elastic modulus of the inner layer of the stress buffer layer 104 is, the more the stress peak value is shifted to the inside of the stress buffer layer 104.

In one embodiment of the present disclosure, the functional wear layer 102, the stress buffer layer 104, and the fracture-resistant substrate layer 106 are non-homogeneous, unitary structures formed by a curing process.

In one embodiment of the present disclosure, the stabilizer of the functional wear layer 102 includes one of cerium oxide, magnesium oxide, calcium oxide, yttrium oxide, strontium oxide, niobium oxide, ytterbium oxide, erbium oxide, and holmium oxide.

In one embodiment of the present disclosure, the stabilizer of the functional wearing layer 102 is 8 mol% to 12 mol% cerium oxide, or 8 mol% to 12 mol% magnesium oxide, or 8 mol% to 12 mol% calcium oxide, or 3 mol% to 5 mol% yttrium oxide, or 8 mol% to 12 mol% strontium oxide, or 8 mol% to 12 mol% niobium oxide.

In one embodiment of the present disclosure, the stabilizer of the stress buffer layer 104 includes at least two of cerium oxide, magnesium oxide, calcium oxide, yttrium oxide, strontium oxide, niobium oxide, ytterbium oxide, erbium oxide, and holmium oxide.

In an embodiment of the disclosure, the stabilizer of the stress buffer layer 104 is 8 mol% to 12 mol% of cerium oxide and 8 mol% to 12 mol% of magnesium oxide, or 8 mol% to 12 mol% of cerium oxide and 8 mol% to 12 mol% of calcium oxide, or 8 mol% to 12 mol% of cerium oxide and 3 mol% to 5 mol% of yttrium oxide, or 8 mol% to 12 mol% of magnesium oxide and 8 mol% to 12 mol% of calcium oxide, or 8 mol% to 12 mol% of magnesium oxide and 3 mol% to 5 mol% of yttrium oxide, or 8 mol% to 12 mol% of calcium oxide and 3 mol% to 5 mol% of yttrium oxide.

In one embodiment of the present disclosure, the stabilizer of the anti-fracture substrate layer 106 includes 3 mol% to 5 mol% yttria.

Fig. 2 shows a flow chart of a method for preparing a bionic enamel zirconia ceramic material block in an embodiment of the disclosure.

As shown in fig. 2, a method for preparing a piece of biomimetic enamel zirconia ceramic material according to an embodiment of the present disclosure includes:

step S202, processing the zirconia nano-crystal to obtain zirconia ceramic powder containing a stabilizer.

In the above embodiment, the processing of the zirconia nanocrystal includes three steps of a hydrothermal reaction, a hydrolysis reaction, and obtaining of powder:

(1) hydrothermal reaction

Preparing a mixed aqueous solution of zirconium oxychloride and carbamide with a certain volume and a certain concentration to finally form [ Zr ]⁴⁺]＝0.4mol/L，[CO(NH₂)₂]1mol/L of the reaction feed. And (3) placing the reaction liquid in a hydrothermal synthesis reaction kettle with a polytetrafluoroethylene lining, and reacting for 3 hours at the temperature of 150 +/-10 ℃ to generate gel.

(2) Hydrolysis reaction

Taking out the gel obtained after the hydrothermal reaction, adding a certain amount of raw reaction liquid, stirring the solution in a flask provided with a reflux condenser, and simultaneously continuing the hydrolysis reaction at the boiling temperature, wherein the conversion rate of the obtained hydrous zirconia sol is 99%. Yttrium nitrate is added to the hydrous zirconia sol so that the yttria concentration is in the range of 3% (mole fraction) to 5% (mole fraction).

(3) Obtaining of powder

The resulting mixture was dried and calcined at 1140 c 10 c for 2h, and the resulting calcined powder was washed with deionized water followed by absolute ethanol until the filtrate was free of chloride ions. Drying the filter cake at the temperature of 80 +/-10 ℃ for 12 hours, and grinding and screening to obtain the zirconia ceramic powder.

Step S204, pressing the zirconia ceramic powder by an isostatic pressing method to obtain a functional wearing layer, wherein the functional wearing layer is used for simulating a straight glaze column layer of natural tooth enamel.

In the above embodiment, the zirconia ceramic powder is pressed by an isostatic pressing method to obtain a functional wearing layer, which is used for simulating a straight glaze column layer of natural tooth enamel, so that the density and rigidity of the functional wearing layer are reduced, the wear of the dental prosthesis on the jaw teeth can be effectively reduced, and the service life of the dental prosthesis and the jaw teeth can be prolonged.

Wherein, the isostatic pressing technology comprises three different types of cold isostatic pressing, warm isostatic pressing and hot isostatic pressing. The molding of the zirconia ceramics includes dry pressing, isostatic pressing, injection molding, slip casting, hot injection molding, tape casting, plastic extrusion molding, colloidal solidification molding, etc., and preferably, isostatic pressing, injection molding, dry pressing, etc., can be used, but is not limited thereto.

In addition, the preparation parameters of the zirconia ceramic material block can be determined through a simulated stress technology, firstly, a three-dimensional curved surface finite element model of the bionic enamel zirconia ceramic material block is constructed, the model is subjected to fine mesh division, and the stress condition of an actual tooth body is simulated by loading vertical and oblique bite force.

Finally, a first-order method in ANSYS software can be adopted to perform optimization calculation by taking the elastic modulus change of the functional gradient as a target function, and optimal elastic modulus gradient change curves under the conditions of vertical loading and oblique loading are respectively obtained. Finally, parameters of the isostatic pressing step, such as the sintering time, the sintering temperature, etc., are determined based on the elastic modulus gradient curve, but not limited thereto.

Based on the steps shown in fig. 2, as shown in fig. 3, the method for preparing the bionic dentin zirconia ceramic material block according to the embodiment of the disclosure further includes:

step S302, pressing the zirconia ceramic powder by an isostatic pressing method to obtain a stress buffer layer with micro-nano pores, wherein the stress buffer layer is used for simulating a twisted glaze column layer of the natural tooth enamel.

Step S302, forming the stress buffer layer and the functional wear layer into a non-homogeneous integrated structure, where the stress buffer layer can buffer stress from the power consumption wear layer.

In the above embodiment, the zirconia ceramic powder is pressed by an isostatic pressing method to obtain a stress buffer layer with micro-nano-scale pores, the stress buffer layer is used for simulating a twisted glaze column layer of the natural tooth enamel, and the stress buffer layer and the functional wearing layer are formed into a non-homogeneous integrated structure, so that the stress buffer layer can buffer the stress from the power consumption wearing layer, the functional wearing layer deforms along with the fracture and compression of the chewing process of a patient, the shape of the dental prosthesis better meets the chewing requirement, the hardness and the wear resistance of the dental prosthesis are reduced, the conditions of jaw tooth trauma, occlusal trauma, temporomandibular joint disorder and the like are reduced, and the service life of the jaw tooth and the dental prosthesis is favorably optimized.

Based on the steps shown in fig. 2, as shown in fig. 4, the method for preparing the bionic dentin zirconia ceramic material block according to the embodiment of the disclosure further includes:

step S402, the zirconia ceramic powder is pressed by an isostatic pressing method to obtain a fracture-resistant base layer.

Step S404, forming the anti-bending substrate layer and the stress buffer layer into a non-homogeneous integrated structure, where the anti-bending substrate layer can support the stress buffer layer.

In the above embodiment, the fracture-resistant substrate layer and the stress buffer layer are formed into a non-homogeneous integrated structure, and the fracture-resistant substrate layer can support the stress buffer layer, so that the probability of fracture of the dental prosthesis is reduced on the premise of ensuring the reliable structures of the functional wearing layer and the stress buffer layer.

Fig. 5 shows a flow chart of a method for preparing a dental restoration made of a biomimetic enamel zirconia ceramic material according to an embodiment of the present disclosure.

As shown in fig. 5, a method for preparing a dental restoration of a biomimetic enamel zirconia ceramic material according to an embodiment of the present disclosure includes:

step S502, constructing a three-dimensional digital model of the dental prosthesis.

And step S504, importing the three-dimensional digital model and the preset size of the three-dimensional digital model into a tool path planning program of the numerical control cutting equipment.

And S506, controlling the data cutting equipment through the tool path planning program, and cutting the bionic tooth enamel zirconium oxide ceramic material block according to the three-dimensional digital model to obtain the tooth restoration body made of the bionic tooth enamel zirconium oxide ceramic material.

In the above embodiment, the data cutting device is controlled by the tool path planning program, and the bionic enamel zirconium oxide ceramic material block is cut according to the three-dimensional digital model to obtain the dental prosthesis of the bionic enamel zirconium oxide ceramic material, so that the wear of the dental prosthesis on the jaw teeth can be effectively reduced, the service lives of the dental prosthesis and the jaw teeth can be prolonged, the possibility of breakage of the dental prosthesis after long-term use can be reduced, the reliability of the dental prosthesis can be further improved, the possibility of breakage of the dental prosthesis after long-term use can be reduced, and the reliability of the dental prosthesis can be further improved.

Based on the steps shown in fig. 5, as shown in fig. 6, the step of controlling the data cutting device by the tool path planning program to cut the bionic tooth enamel zirconium oxide ceramic material block according to the three-dimensional digital model to obtain the dental prosthesis of the bionic tooth enamel zirconium oxide ceramic material comprises:

step S6062, acquiring a data model of the bionic enamel zirconia ceramic material block to be cut.

Step S6064, matching and aligning the three-dimensional digital model and the data model of the bionic dental enamel zirconium oxide ceramic material block until the three-dimensional digital model is contained in the data model of the bionic dental enamel zirconium oxide ceramic material block.

In the above embodiment, the three-dimensional digital model and the data model of the bionic dental enamel zirconia ceramic material block are aligned in a matching manner until the three-dimensional digital model is contained in the data model of the bionic dental enamel zirconia ceramic material block, so that the dental prosthesis obtained by cutting has no defect and is consistent with the three-dimensional digital model in height.

Step S6066, generating cutting information according to the matching and aligning result, wherein the cutting information comprises at least one of cutting orientation, cutting angle and cutting distance.

Step S6068, the tool path planning program sends the cutting information to the data cutting equipment so that the data cutting equipment can cut the bionic enamel zirconium oxide ceramic material block to obtain a tooth restoration body model of the bionic enamel zirconium oxide ceramic material.

In the embodiment, the bionic enamel zirconium oxide ceramic material block is cut by the data cutting equipment to obtain the dental prosthesis model of the bionic enamel zirconium oxide ceramic material, so that the abrasion of the dental prosthesis on jaw teeth can be effectively reduced, the probability of breakage of the dental prosthesis is reduced, and the service lives of the dental prosthesis and the jaw teeth are prolonged.

Based on the steps shown in fig. 5 and fig. 6, as shown in fig. 7, controlling the data cutting device by the tool path planning program, and cutting the bionic enamel zirconium oxide ceramic material block according to the three-dimensional digital model to obtain the dental prosthesis of the bionic enamel zirconium oxide ceramic material further includes:

step S7062, sintering and polishing the obtained dental prosthesis model of the bionic dental enamel zirconia ceramic material to obtain the dental prosthesis of the bionic dental enamel zirconia ceramic material.

In the embodiment, the surface of the dental restoration is smoother and more reliable through sintering and polishing the dental restoration model, the appearance of the dental restoration is highly similar to that of natural teeth, namely, the transmittance, the transparency and the color are very close to each other, and the use experience of a user is further improved.

Fig. 8 shows a schematic view of a dental restoration of a biomimetic enamel zirconia ceramic material in an embodiment of the present disclosure.

As shown in fig. 8, the dental restoration 800 made of the bionic enamel zirconia ceramic material according to the embodiment of the present disclosure is prepared by the method for preparing the dental restoration 800 made of the bionic enamel zirconia ceramic material according to any one of the above technical solutions.

In one embodiment of the present disclosure, the dental prosthesis of a biomimetic enamel zirconia ceramic material further comprises: the non-homogeneous integrated structure comprises a functional wearing layer 802, a stress buffer layer 804 and an anti-bending base layer 806, wherein the functional wearing layer 802 is used for simulating a straight glaze column layer of natural tooth enamel, the stress buffer layer 804 is a micro-nano-grade pore and is used for simulating a twisted glaze column layer of the natural tooth enamel and buffering stress from the power consumption wearing layer, and the anti-bending base layer 806 is used for supporting the stress buffer layer 804.

In the above embodiment, the functional wear layer 802, the stress buffer layer 804 and the fracture-resistant substrate layer 806 having the non-homogeneous integrated structure can effectively reduce the wear of the dental prosthesis on the jaw teeth, thereby being beneficial to prolonging the service life of the dental prosthesis and the jaw teeth, reducing the possibility of fracture of the dental prosthesis after long-term use, being beneficial to further improving the reliability of the dental prosthesis, reducing the possibility of fracture of the dental prosthesis after long-term use, and being beneficial to further improving the reliability of the dental prosthesis.

In one embodiment of the present disclosure, the dental prosthesis 800 has a functional wear layer 802 having a thickness in the range of 0.3mm to 0.6mm, the outer surface of the functional wear layer 802 having an occlusal surface 808.

In one embodiment of the present disclosure, the stress buffer layer 804 of the dental restoration 800 has a thickness in the range of 0.1mm to 0.2 mm.

In one embodiment of the present disclosure, the thickness of the fracture-resistant base layer 806 of the dental prosthesis 800 ranges from 0.5mm to 1 cm.

In one embodiment of the present disclosure, the dental prosthesis 800 has an overall thickness in the range of 1mm to 2 cm.

The preparation scheme of the dental prosthesis comprising the functional wearing layer, the stress buffer layer and the fracture-resistant basal layer at least comprises the following embodiments:

example 1:

the preparation method of the bionic enamel zirconium oxide ceramic material block comprises the following steps:

(1) and designing a zirconia material block consisting of three layers of materials of a functional wearing layer, a stress buffer layer and an anti-bending base layer.

(2) Respectively preparing zirconia ceramic powder for the functional wearing layer, the stress buffer layer and the anti-bending basal layer by adopting a hydrothermal method; wherein, the functional wearing layer is 10 mol% of cerium oxide, the anti-bending basal layer is 3 mol% of yttrium oxide, and the stress buffer layer is 10 mol% of cerium oxide and 3 mol% of yttrium oxide.

(3) Pressing the material blocks/discs in a layering manner by an isostatic pressing method, wherein the thickness of the functional wear layer is 0.3mm, the thickness of the stress buffer layer is 0.1mm, and the thickness of the anti-bending base layer is 0.5 mm; the three-layer structure of the material block/disc is respectively as follows from top to bottom: the functional wearing layer is used for simulating a straight enamel column layer of natural tooth enamel, and the stress buffer layer is used for simulating a twisted enamel column layer of the natural tooth enamel. And then pressed into a monolith. Pre-sintering is performed to form a complete block/disc of material.

Example 2:

the preparation method of the bionic enamel zirconium oxide ceramic material block comprises the following steps:

(1) and designing a zirconia material block consisting of three layers of materials of a functional wearing layer, a stress buffer layer and an anti-bending base layer.

(2) And respectively preparing zirconia ceramic powder for the functional wearing layer, the stress buffer layer and the anti-bending basal layer by adopting a hydrothermal method. Wherein the functional wearing layer is 8 mol% of magnesium oxide, the anti-bending base layer is 5 mol% of yttrium oxide, and the stress buffer layer is 12 mol% of cerium oxide and 10 mol% of magnesium oxide.

(3) The blocks/discs were pressed in layers by isostatic pressing, with a functional wearing layer having a thickness of 0.4mm, a stress buffer layer having a thickness of 0.18mm and an anti-fracture base layer having a thickness of 1.2 mm. The three-layer structure of the material block/disc is respectively as follows from top to bottom: the functional wearing layer is used for simulating a straight enamel column layer of natural tooth enamel, and the stress buffer layer is used for simulating a twisted enamel column layer of the natural tooth enamel. And then pressed into a monolith. Pre-sintering is performed to form a complete block/disc of material.

Example 3:

the preparation method of the bionic enamel zirconium oxide ceramic material block comprises the following steps:

(1) and designing a zirconia material block consisting of three layers of materials of a functional wearing layer, a stress buffer layer and an anti-bending base layer.

(2) And respectively preparing zirconia ceramic powder for the functional wearing layer, the stress buffer layer and the anti-bending basal layer by adopting a hydrothermal method. Wherein, the functional wearing layer is calcium oxide with 12mol percent, the anti-bending basal layer is yttrium oxide with 5mol percent, and the stress buffer layer is cerium oxide with 10mol percent and calcium oxide with 8mol percent.

(3) The blocks/discs were pressed in layers by isostatic pressing, with a functional wearing layer having a thickness of 0.6mm, a stress buffer layer having a thickness of 0.1mm and an anti-fracture base layer having a thickness of 1.0 mm. The three-layer structure of the material block/disc is respectively as follows from top to bottom: the functional wearing layer is used for simulating a straight enamel column layer of natural tooth enamel, and the stress buffer layer is used for simulating a twisted enamel column layer of the natural tooth enamel. And then pressed into a monolith. Pre-sintering is performed to form a complete block/disc of material.

Example 4:

the preparation method of the bionic enamel zirconium oxide ceramic material block comprises the following steps:

(1) and designing a zirconia material block consisting of three layers of materials of a functional wearing layer, a stress buffer layer and an anti-bending base layer.

(2) And respectively preparing zirconia ceramic powder for the functional wearing layer, the stress buffer layer and the anti-bending basal layer by adopting a hydrothermal method. Wherein, the functional wearing layer is cerium oxide with the concentration of 12 mol%, the anti-bending basal layer is yttrium oxide with the concentration of 4 mol%, and the stress buffer layer is magnesium oxide with the concentration of 8 mol% and calcium oxide with the concentration of 10 mol%.

(3) The blocks/discs were pressed in layers by isostatic pressing, with a functional wearing layer having a thickness of 0.5mm, a stress buffer layer having a thickness of 0.19mm and an anti-fracture base layer having a thickness of 1.2 mm. The three-layer structure of the material block/disc is respectively as follows from top to bottom: the functional wearing layer is used for simulating a straight enamel column layer of natural tooth enamel, and the stress buffer layer is used for simulating a twisted enamel column layer of the natural tooth enamel. And then pressed into a monolith. Pre-sintering is performed to form a complete block/disc of material.

Example 5:

the preparation method of the bionic enamel zirconium oxide ceramic material block comprises the following steps:

(1) and designing a zirconia material block consisting of three layers of materials of a functional wearing layer, a stress buffer layer and an anti-bending base layer.

(2) And respectively preparing zirconia ceramic powder for the functional wearing layer, the stress buffer layer and the anti-bending basal layer by adopting a hydrothermal method. Wherein, the functional wearing layer is 10mol percent of magnesium oxide, the anti-bending basal layer is 3mol percent of yttrium oxide, and the stress buffer layer is 10mol percent of magnesium oxide and 3mol percent of yttrium oxide.

(3) The blocks/discs were pressed in layers by isostatic pressing, with a functional wearing layer having a thickness of 0.6mm, a stress buffer layer having a thickness of 0.2mm and an anti-fracture base layer having a thickness of 1.0 mm. The three-layer structure of the material block/disc is respectively as follows from top to bottom: the functional wearing layer is used for simulating a straight enamel column layer of natural tooth enamel, and the stress buffer layer is used for simulating a twisted enamel column layer of the natural tooth enamel. And then pressed into a monolith. Pre-sintering is performed to form a complete block/disc of material.

Example 6:

the preparation method of the bionic enamel zirconium oxide ceramic material block comprises the following steps:

(1) and designing a zirconia material block consisting of three layers of materials of a functional wearing layer, a stress buffer layer and an anti-bending base layer.

(2) And respectively preparing zirconia ceramic powder for the functional wearing layer, the stress buffer layer and the anti-bending basal layer by adopting a hydrothermal method. Wherein, the functional wearing layer is calcium oxide with 8mol percent, the anti-bending basal layer is yttrium oxide with 5mol percent, and the stress buffer layer is calcium oxide with 12mol percent and yttrium oxide with 4mol percent.

(3) The blocks/discs were pressed in layers by isostatic pressing, with a functional wearing layer having a thickness of 0.5mm, a stress buffer layer having a thickness of 0.17mm and an anti-fracture base layer having a thickness of 1.2 mm. The three-layer structure of the material block/disc is respectively as follows from top to bottom: the functional wearing layer is used for simulating a straight enamel column layer of natural tooth enamel, and the stress buffer layer is used for simulating a twisted enamel column layer of the natural tooth enamel. And then pressed into a monolith. Pre-sintering is performed to form a complete block/disc of material.

The preparation method of the other bionic enamel zirconia ceramic material dental prosthesis comprises the following steps:

(1) a three-dimensional digital model of the dental restoration is designed in a dental restoration CAD program.

(2) And importing the digital model into a tool path planning program of the numerical control cutting equipment.

(3) In the tool path planning program, virtual material data of a zirconium oxide material block/disc which has preset sizes, is provided with a functional wearing layer, a stress buffer layer and an anti-bending basal layer and can be cut is called.

(4) And placing the designed dental prosthesis three-dimensional digital model in the data contour of the zirconia material block/disc virtual material with the same actual size as the zirconia material block/disc, and ensuring that the whole surface of the dental prosthesis three-dimensional digital model is positioned in the zirconia material block/disc virtual material data and matched with the degree of freedom of the used cutting equipment.

(5) And generating a cutting file from the typeset data, and inputting the cutting file into numerical control cutting equipment capable of running a tool path planning program to carry out automatic cutting.

(6) The cut prosthesis can be delivered to clinical use after final sintering and polishing.

Wherein, step (4) also includes the step: ensuring that the occlusal surface part of the dental prosthesis three-dimensional digital model sequentially comprises a functional wearing layer, a stress buffer layer and an anti-bending basal layer in zirconia material block/disc virtual material data from the surface to the inside, wherein the thickness of the functional wearing layer of the occlusal surface part is 0.3mm-0.6mm, the thickness of the stress buffer layer of the occlusal surface part is 0.1mm-0.2mm, and the thickness of the anti-bending basal layer of the occlusal surface part is 0.5mm-1 cm. The total thickness of the manufactured prosthesis is 1mm-2 cm. Meanwhile, the axial surface area of the dental prosthesis three-dimensional digital model is arranged on the anti-bending basal layer of the zirconia material block/disc virtual material data.

The finally prepared dental restoration part sequentially comprises a bionic abrasion layer, a stress buffer layer and an anti-bending basal layer in the zirconium oxide blank block/disc virtual material data from the surface to the inside, and the axial surface area of the dental restoration only comprises the anti-bending basal layer. Therefore, the problem of excessive wear of the high-strength single-layer full zirconia dental prosthesis on the jaw teeth can be solved, the problem of no stress buffering in full-ceramic implant repair can be solved, and the problem that the prosthesis is easy to break off in a long term when all bionic wear-resistant ceramic materials are applied can be solved.

The main stress concentration areas of the dental restoration body in the chewing process are occlusal surfaces and shoulder areas, in order to avoid tooth fracture (which is frequently caused by excessive occlusal force), the stress concentration areas (the bottommost layer and the axial surface of the occlusal surface) are designed into a fracture-resistant base layer material with the strongest fracture resistance, so that the bionic physiological abrasion of a functional abrasion layer and the stress dissipation of a stress buffer layer bionic twisted glaze column layer can be realized, and the fracture of the restoration body is less prone to surpass natural teeth. If the lowermost layer of the occlusal surface is not provided with the fracture-resistant base layer, fracture of the prosthesis originating from the occlusal surface may occur.

The single-layer full zirconium crown has an abrasion resistance 8.6 times that of natural tooth enamel, as detailed in table 1 below.

TABLE 1

Name (R)	Hardness (GP)a)	Modulus of elasticity (Mp)a)	Abrasion loss (mm)3)
				Zirconium oxide	16	270	0.022±0.007
Tooth enamel	3.5	81	0.19±0.11

The dental restoration manufactured in examples 1-6 of the present disclosure has a fracture rate of < 10%, while the dental restoration of the resin-ceramic composite material has a long-term fracture rate of > 80%.

The dental prosthesis produced in examples 1-6 of the present disclosure has a strong direct bond between the implant and the bone, with a cushioned motion scale of only 5 microns, while the natural periodontal ligament has a cushioned motion scale of 30-100 microns.

The dental prosthesis manufactured in embodiments 1 to 6 of the present disclosure can ensure the semi-permeability of dental zirconia, simulate the opalescent effect of natural tooth enamel, and avoid light scattering and refraction phenomena caused by micro cracks between crystal grains.

According to the program product for implementing the above method of the embodiments of the present disclosure, it may employ a portable compact disc read only memory (CD-ROM) and include program codes, and may be run on a terminal device, such as a personal computer. However, the program product of the present disclosure is not limited thereto, and in this document, a readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device.

A computer readable signal medium may include a propagated data signal with readable program code embodied therein, for example, in baseband or as part of a carrier wave. Such a propagated data signal may take many forms, including, but not limited to, electro-magnetic, optical, or any suitable combination thereof. A readable signal medium may also be any readable medium that is not a readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device.

Program code embodied on a readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

Program code for carrying out operations for the present disclosure may be written in any combination of one or more programming languages, including an object oriented programming language such as Java, C + + or the like and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The program code may execute entirely on the user's computing device, partly on the user's device, as a stand-alone software package, partly on the user's computing device and partly on a remote computing device, or entirely on the remote computing device or server. In the case of a remote computing device, the remote computing device may be connected to the user computing device through any kind of network, including a Local Area Network (LAN) or a Wide Area Network (WAN), or may be connected to an external computing device (e.g., through the internet using an internet service provider).

It should be noted that although in the above detailed description several modules or units of the device for action execution are mentioned, such a division is not mandatory. Indeed, the features and functionality of two or more modules or units described above may be embodied in one module or unit, according to embodiments of the present disclosure. Conversely, the features and functions of one module or unit described above may be further divided into embodiments by a plurality of modules or units.

Moreover, although the steps of the methods of the present disclosure are depicted in the drawings in a particular order, this does not require or imply that the steps must be performed in this particular order, or that all of the depicted steps must be performed, to achieve desirable results. Additionally or alternatively, certain steps may be omitted, multiple steps combined into one step execution, and/or one step broken down into multiple step executions, etc.

Through the above description of the embodiments, those skilled in the art will readily understand that the exemplary embodiments described herein may be implemented by software, or by software in combination with necessary hardware. Therefore, the technical solution according to the embodiments of the present disclosure may be embodied in the form of a software product, which may be stored in a non-volatile storage medium (which may be a CD-ROM, a usb disk, a removable hard disk, etc.) or on a network, and includes several instructions to enable a computing device (which may be a personal computer, a server, a mobile terminal, or a network device, etc.) to execute the method according to the embodiments of the present disclosure.

Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed herein. This disclosure is intended to cover any variations, uses, or adaptations of the disclosure following, in general, the principles of the disclosure and including such departures from the present disclosure as come within known or customary practice within the art to which the disclosure pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.