Xinxiang Hui'er Ceramics Co., Ltd

　　Zirconia is a mineral found in nature as plagioclase zircon. Medical zirconia undergoes cleaning and processing, resulting in a small amount retained in zirconium α The residual radiation has a very small penetration depth of only 60 microns. It is precisely the unique stability and antioxidant ability of zirconia that is increasingly being used in the production and clinical treatment of dentures.　　"Zirconia all ceramic fused to metal teeth" uses a mechanical scanner to obtain data on models that have undergone tooth preparation and require single crown restoration, jaw models, and bite models of the central teeth. Through computer design and a series of adjustments, data suitable for the individual's single crown is obtained, and the design route of the single crown is obtained. The data is saved in the form of data for subsequent CNC machining programs, and the entire process is computer-controlled, Greatly eliminating errors, accuracy and precision ensure the effectiveness of teeth beautification.　　Zirconia all ceramic is currently a high-strength all ceramic material that can be used for crown and bridge restoration in any area of anterior and posterior teeth. It overcomes the narrow indications of all ceramic materials in the past, significantly expanding the application range of all ceramic aesthetic restoration and driving the development of all ceramic aesthetic restoration, meeting the urgent needs of patients for metal free aesthetic restoration.

　　1. Structure of oral ceramic materials　　(1) Crystal phase: It is the main constituent phase of ceramic materials.　　(2) Glass phase: It is a low melting point solid with an amorphous structure that exists between various grains, bonding grains, improving the density of ceramic materials, reducing sintering temperature, improving process, and suppressing grain growth. The chemical composition of glass phase is mostly SiO2, and the content of glass phase varies for different ceramics.　　(3) Gas phase: also known as pores, most pores are formed and retained during the processing. Some pores can be obtained through special process methods, generally including open pores and closed pores. The porosity, pore size, and morphology distribution have a significant impact on the performance of ceramics. Reasonable control of the number, morphology, and distribution of stomata is extremely important.　　2. Performance of oral ceramic materials　　(1) Physical performance; Oral ceramic materials are thermal insulators with a thermal expansion coefficient similar to human teeth. The main reason for affecting transparency is the presence of pores inside the ceramic. The finer the particles of ceramic powder, the smaller and denser the pores.　　(2) Chemical properties: The chemical properties of oral ceramics are stable in oral materials.　　(3) Biological properties: Oral ceramic materials have good biological properties.　　(4) Aesthetic performance: Oral ceramic materials have good aesthetic performance.

　　Ceramic materials have been used as oral restoration materials for over 200 years. Since Land produced a feldspar all ceramic crown in 1886, all ceramic materials have gradually become a research hotspot. Since the 1960s, scholars have successively added garnet and alumina to feldspar ceramics, improving the mechanical and physical properties of all ceramic materials. In the early 1990s, zirconia ceramics were introduced into the field of dentistry. Due to their excellent flexural strength and fracture toughness, they were quickly applied in various fields, including post core crowns, implants and abutments, orthodontic brackets, fixed bridge brackets, etc.　　Oral ceramic materials have excellent color stability, wear resistance, biocompatibility, as well as excellent optical properties and aesthetics, and occupy an increasingly important position in clinical dental restoration. At the same time, a large number of all ceramic products have emerged on the market, including ceramic like materials launched in recent years. The numerous materials and brands often cause confusion for clinical doctors in their choices. This article categorizes the current mainstream oral ceramics and ceramic like restorative materials based on their microstructure, and provides a review from the aspects of material properties, main products, clinical indications, surface treatment, and bonding. The aim is to elucidate their clinical applications, help clinical doctors understand the characteristics of different ceramic ceramics and ceramic like materials, and make reasonable choices.　　1、 Classification of all ceramic materials　　All ceramic materials are usually composed of two or more phases. According to the different contents of glass phase and crystal phase in the microstructure of ceramic materials, all ceramic materials can be divided into three categories: ① feldspar ceramics mainly composed of glass phase; ② Glass ceramics containing both glass and crystal phases; ③ Polycrystalline ceramics without glass phase.　　1. Feldspar porcelain　　Feldspar porcelain is a type of amorphous glass made by high-temperature sintering of natural feldspar, quartz, and kaolin. Feldspar porcelain is a ceramic material that has long been used in dentistry, and its optical properties are very close to enamel and dentin. However, due to its poor mechanical performance, the flexural strength is usually only 60-70MPa, so it is commonly used as a porcelain fused to metal restoration (PFMS), fused to ceramic restoration (PFCS), or veneer.　　2. Glass ceramics　　Glass ceramics, also known as microcrystalline glass, are a type of composite material made by high-temperature melting, forming, and heat treatment that combines crystal phases with glass. Compared with amorphous glass, the addition or growth of crystal fillers in the glass phase significantly changes the mechanical and optical properties of glass based ceramics, such as increasing the coefficient of thermal expansion and toughness, and changing the color, milkiness, and transparency of the material. According to the different crystal composition, there are several types of glass ceramics commonly used in clinical practice. Leucite reinforced glass ceramics: Leucite (mass fraction 35%~55%) is used as a reinforcing phase in all ceramic materials. Due to its aesthetic similarity to feldspar ceramics, its strength is improved (flexural strength can reach 120-180MPa), and it is more conducive to resin bonding, making it more widely used.　　Although clinical studies have shown that the fracture rate of garnet reinforced glass ceramics is relatively low, the success rate of using it for posterior teeth is significantly lower than that for anterior teeth. Therefore, it is mainly used for single crown restoration with inlays, high inlays, veneers, and anterior teeth. Lithium disilicate glass ceramic: SiO2 Li2O glass ceramic has a high crystal phase content (about 70%), so its flexural strength can reach over 300-400 MPa. Although the crystal phase content is high, the transparency of the material is still high due to the low refractive index of lithium disilicate. It can be directly used as an all ceramic restoration or decorated with fluoroapatite glass ceramics on its surface.　　Except for IPSEpress2, which has lower strength, all other products can be used for three unit fixed bridges with veneer, inlay, high inlay, anterior and posterior single crown, and anterior/premolar area. However, as a fixed bridge, its clinical success rate significantly decreases, mainly due to the fracture at the connection of the fixed bridge. In recent years, improved materials based on this material have begun to emerge. Vita Supernity (VITA) is a zirconia reinforced lithium silicate glass ceramic (ZLS) formed by CAD/CAM in 2013. By using a special process to add zirconia (about 10% specific gravity) to glass ceramics, compared with traditional lithium disilicate glass ceramics, it not only improves the flexural strength (494.5 MPa), but also has good transparency, fluorescence, milky effect, and higher edge stability and accuracy. Moreover, studies have shown that the adhesive strength of ZLS is stronger than that of traditional lithium disilicate glass ceramics.　　Fluorapatite glass ceramics: Glass ceramics containing fluoroapatite crystals [Ca5 (PO4) 3F] are similar to hydroxyapatite crystals in enamel, thus improving the optical properties and thermal expansion coefficient of traditional feldspar ceramics. They are commonly used as decorative ceramics for metal scaffolds, lithium disilicate glass ceramics, and zirconia crowns.　　In Ceram glass infiltrated ceramics: Currently, glass infiltrated ceramics specifically refer to the In Ceram series. In CeramAlumina is an all ceramic system that can be used for single crown and three unit fixed bridge restoration of anterior teeth, with moderate strength (350-450MPa) and transparency. The second generation product, In Ceram Spinel, has increased transparency but decreased strength and is only used for making front dental crowns. In Ceram Zirconia added 35% partially stabilized zirconia, achieving a flexural strength of over 650MPa but almost opaque, making it mainly used for single crowns and three unit fixed bridges in posterior teeth. Although the In Ceram series has a high clinical success rate, its clinical use has gradually decreased with the development of zirconia and other new materials in recent years.　　3. Polycrystalline ceramics　　Polycrystalline ceramics are dense ceramic materials that are directly fired from crystals and do not contain glass or gas phases. They have high strength and hardness and are processed using CAD/CAM equipment. This type of material, due to the lack of glass phase, usually has low transparency and needs to be decorated with decorative ceramics, including alumina and zirconia. Procera All Ceram (Nobel Biocare) is a polycrystalline ceramic early used in the dental field, containing 99% to 99.5% high-purity dense alumina ceramics, with a strength of approximately 600Mpa, second only to zirconia ceramics. However, due to its high elastic modulus, it is prone to material fragmentation, so its clinical use has gradually been replaced by zirconia. The zirconia used for dental materials is tetragonal zirconia polycrystalline (Y-TZP) stabilized with yttrium oxide. It has excellent stability, wear resistance, and biocompatibility, with a flexural strength of 900-1200Mpa and a fracture toughness of 9-10MPa/m1/2, which is twice that of dense alumina and three times that of lithium disilicate glass ceramics. It is commonly used for posterior crown and multi unit fixed bridge repairs.　　The main reason for the failure of zirconia restoration in clinical practice is the cracking of decorative porcelain. Although processing methods that slow down heating and cooling rates can improve the rate of ceramic failure, there are currently few clinical literature reports on such methods. Compared with traditional zirconia crown with decorative porcelain, all zirconia restorations have the following advantages: ① No need for decorative porcelain, avoiding porcelain collapse, and achieving significant results in fixed bridge restoration for posterior teeth. Ramos et al.'s in vitro fatigue tests showed that under continuous action of the piston (100N, 3Hz) × After 106 cycles, the failure rate of all zirconia restorations is much lower than that of traditional zirconia A smaller amount of tooth preparation preserves more dental tissue, making it suitable for cases with insufficient facial space. Taking the all zirconia restoration VitaYZT (VITA) as an example, its posterior teeth have a full crown reserve of face ≥ 0.7mm, adjacent face ≥ 0.5mm, and shoulder ≥ 0.2mm, which is much smaller than the traditional zirconia plus porcelain full crown reserve (face ≥ 1.4mm, adjacent face ≥ 1.2mm, shoulder ≥ 0.5mm) With the development of materials, new types of high permeability all zirconia restorations continue to emerge, improving the transparency of zirconia materials. As introduced in 2014, PRETTUANTERIOR (Zirkonzahn) has the same transparency as lithium disilicate glass ceramics, and its strength is much higher than that of glass ceramics (>670MPa), which can greatly replace glass ceramics as an aesthetic restoration for anterior teeth Less wear on natural teeth in the opposite jaw. Studies have shown that although the hardness of zirconia is much higher than that of glass ceramics, highly polished all zirconia restorations have a lower degree of wear on natural teeth in the opposite jaw compared to glass ceramics. 3M Monolith and 3M Translucent (3MESPE) can also be used for patients with night molars (single crown or three unit fixed bridge). Although all zirconia restorations have many advantages, due to the lack of decorative porcelain, zirconia materials have low-temperature aging phenomenon when used in hydrothermal environments for a long time. The impact of whether the surface of the restorations is highly polished in clinical operations on friction performance and the strength reduction brought about by aesthetic performance improvement still require long-term clinical practice to confirm and improve.　　2、 Resin ceramic composite materials/ceramic like materials　　With the continuous development of aesthetic restoration, new types of glass ceramics and polycrystalline ceramics are constantly emerging, but these materials usually require a time-consuming heat treatment process before clinical application. Moreover, the elastic modulus of materials currently used for repairing dental defects is much lower than (polymer composite materials) or much higher than (ceramic materials) the elastic modulus of enamel and dentin. Therefore, in recent years, a new type of CAD/CAM resin ceramic composite material has begun to appear in the market, which is highly filled with ceramic particles (>50% weight) in organic scaffolds. Some scholars believe that according to the definition of ceramics in the 2013 ADA Dental Regulations and Naming Rules, composite materials composed mainly of ceramic materials and supplemented by organic polymers can be classified as ceramic materials. However, there is still controversy surrounding this issue internationally. Therefore, this article will separately introduce this type of material as a type of ceramic material.　　Compared with traditional ceramic materials, it has special properties due to the presence of organic scaffolds, which have the following advantages: ① closer elastic modulus to dentin; ② Reduced the brittleness and hardness of the material, making it easier to cut; ③ More convenient to use resin for repair; ④ After adjustment, it does not affect the intensity and is easy to operate clinically; ⑤ The wear on natural teeth is much smaller than that on glass ceramics; ⑥ No heat treatment is required, and its design and production can be completed next to the chair. VitaEnamic (VITA), launched in 2013, is a resin ceramic composite material in the world, consisting of a dual network structure of 86% weight feldspar glass ceramic and resin polymer. Its strength is about 150-160MPa, and its elastic modulus is about 30GPa, very close to dentin. Some scholars classify it as glass infiltrated ceramics. Compared with traditional dental ceramic materials, its toughness and elasticity are enhanced, and its wear resistance, strength, and color change resistance are superior to existing resin materials. The degree of wear is similar to that of natural enamel. Simultaneously possessing high transparency, it can effectively complete the aesthetic restoration of front teeth. In addition, the machinability and edge stability of the material are superior to other CAD/CAM ceramics. Its small tooth preparation amount is also smaller than that of glass ceramics, making it suitable for veneers, inlays, high inlays, single crowns, and minimally invasive restorations, such as in cases where the preparation amount is significantly insufficient and the repair space is very limited.　　Lava Ultimate (3MESPE) is a resin nanoceramic formed by filling approximately 80% weight of SiO2, ZrO2, and polymer SiO2/ZrO2 nanoceramic fillers in processed resin scaffolds. It has good aesthetic performance and durability, with a high strength of 200Mpa, and can be used as a restoration for posterior teeth. In clinical application, due to the possibility of debonding as a single crown, its application is limited compared to VitaEnamic. It is only used for inlays, high inlays, and veneers, and the preparation of teeth for inlays and high inlays must ensure maximum internal fixation design.　　At present, this type of material still has some defects, such as inferior wear resistance and light transmittance compared to glass ceramics, and research is still limited to in vitro experiments, with limited clinical literature reporting.　　3、 Surface treatment and bonding　　In clinical practice, a very important factor affecting the indications and success rate of ceramics and ceramic like restorative materials is the adhesion of the materials. The recommended bonding methods vary for ceramic materials with different compositions. Currently, ceramic adhesive resin adhesives are used in clinical practice. The commonly used methods in clinical practice to increase the adhesive strength of ceramic materials containing glass matrix (feldspar ceramics, glass ceramics) are hydrofluoric acid etching and surface silanization. Due to the presence of a large number of Si-O bonds in the structure, micro grooves and small pores can be formed by hydrofluoric acid etching, which creates a mechanical locking effect between the ceramic surface and the resin, thereby improving the bonding strength. The best etching effect is achieved by using a hydrofluoric acid solution with a concentration of 2.5% to 10% for 2.0 to 3.0 minutes. However, it is worth noting that glass infiltrated ceramics have a low content of glass components, and acid etching is not sufficient to make their surface rough enough. Therefore, acid etching treatment is usually not used in clinical practice. Silane coupling agents can form covalent and hydrogen bonds with SiO2 on the surface of ceramics, while copolymerizing with resin, significantly improving the bonding strength. Therefore, ceramic materials containing glass matrix have good adhesive strength, and for restorations with poor retention, such as ceramic veneers, inlays, and high inlays, their reliability is high. Clinical evaluation shows a 5-year success rate of 93% to 98%, and a 10-year success rate of 64% to 95%.　　Polycrystalline ceramics cannot be etched by traditional acid etchants because they do not contain glass components, so their adhesive strength is not as strong as glass ceramics, especially zirconia ceramics. Their application is greatly controlled by their adhesive properties, so it is not recommended to use them as veneers. Inokoshi et al. reviewed a large number of literature and found that the surface modification of zirconia (chemical friction silicon coating or Al2O3 sandblasting) using treatment agents and adhesives containing phosphate esters (MDP) has high and long-lasting bonding strength. The surface treatment method of VitaEnamic is similar to that of traditional glass ceramics, as the glass component on its surface can be selectively removed by hydrofluoric acid, exposing the resin support and increasing the roughness. It is recommended to use hydrofluoric acid etching and surface silanization. Research has shown that its adhesive performance is reliable, with a strength higher than Lava Ultimate, equal to Vitalocs MarkII, and slightly lower than lithium disilicate glass-ceramic (IPSe. maxCAD) and ZLS (VitaSuprinity, CellraDuo). LavaUltimate cannot be treated with hydrofluoric acid or phosphoric acid, and adhesives containing clove oil cannot be used as temporary restorations. It should be noted that resin ceramic composite materials can only use resin adhesives as restorations at present.　　In summary, oral ceramics and ceramic like restorative materials have developed rapidly in recent decades, and there will be more developments and breakthroughs in the near future. Faced with an increasing number of choices, clinical doctors should have a better understanding of the classification and characteristics of materials, and make reasonable choices based on their strength, transparency, adhesive properties, etc., while considering the patient's economic ability and abutment conditions.

　　Oral ceramic materials　　Oral restorations made of specialized ceramic materials have excellent translucency, high color simulation, and good biocompatibility, making them currently the most aesthetically pleasing and promising restorations. However, due to the high brittleness and susceptibility to cracking of ceramic materials, they are currently mainly used in the production of front dental crowns, veneers, and other materials.　　1、 Classification of Oral Ceramic Materials　　（1） Temperature classification　　1. The sintering temperature of high melting porcelain is 1290-1370 ℃.　　2. The sintering temperature of medium melting porcelain is 1090-1260 ℃.　　3. The sintering temperature of low melting porcelain is 870~1065 ℃.　　High melting porcelain was once used to make porcelain crowns, but now it is usually used to make finished porcelain teeth. A typical high melting porcelain is composed of feldspar (70% -90%), quartz (11% -18%), and kaolin (1% -10%). The main component of feldspar is silicon oxide, manifested in the forms of NaOAl2O36SiO2 and K2OAl2O6SiO2. When melted, it forms a glassy substance, producing the translucency of ceramics. It serves as a matrix for high melting quartz (SiO2), while the latter forms a refractory skeleton structure. Fusion of other materials around it. This is very helpful for maintaining the shape of porcelain restorations during the sintering process. Kaolin, a clay like substance, is a sticky substance. When porcelain is not formed or sintered, it can combine particles together.　　Low melting porcelain and medium melting porcelain are made through a so-called glass melting process. The crude raw materials of porcelain are melted, quenched, and crushed into very small powders. When sintered again to make the restoration, this powder melts at low temperatures and no longer undergoes high-temperature reactions.　　Adding a certain amount of metal oxides (zirconia, titanium oxide, and tin oxide) can make the porcelain opaque. The opaque porcelain layer is used to cover the metal base crown of the metal ceramic restoration. Adding a certain amount of other metal substances during the sintering process can produce the color of porcelain, such as indium (yellow), chromium, tin (pink), iron oxide (black), and cobalt salts (blue).　　（2） Component classification　　1. Feldspar ceramics　　The main raw material for feldspar ceramics is feldspar, while the feldspar used in oral feldspar ceramics is a mixture of natural sodium feldspar (Na2O. Al2O3.6SiO2) and potassium feldspar (K2O. Al2O3.6SiO2). The basic components of feldspar porcelain are feldspar, quartz, and white clay. Feldspar porcelain has good biological properties and can be used as a porcelain powder material and to make finished teeth and tooth surfaces. Due to its bending strength being only 50-80 MPa, it needs to be used in conjunction with high-strength alloys or ceramics. Currently, it is commonly used in clinical practice to make porcelain fused to metal restorations (PFMS) and porcelain fused to ceramic restorations (PFCS).　　2. Glass ceramics　　Glass ceramics are polycrystalline solids made from ordinary glass through microcrystalline treatment, with more crystalline phases than glass phases. It can be used to make crown and bridge restorations and serve as an implant material. The commonly used glass ceramics in clinical repair include cast glass ceramics, cut glass ceramics, injection glass ceramics, and implanted glass ceramics.　　3. Aluminum oxide ceramics　　The main crystal phase is a-Al2O3. It is made by dispersing a certain amount of alumina crystals in a glass matrix, and its essence is a type of glass ceramic. The bending strength of aluminum ceramic used for oral restoration increases with the increase of aluminum oxide content, which is above 50wt%.　　4. Hydroxyapatite Ceramic Hydroxyapatite ceramic, with a molecular formula of Ca10 (PO4) 6 (OH) 2. Due to its structure being similar to the inorganic components of human dental bone tissue, artificially synthesized hydroxyapatite ceramic has good biocompatibility, can form a good structure with the cell membrane surface, and form a bony bond with bone tissue, making it a good substitute material for dental and bone defects.　　（3） Classification of Forming Technologies　　1. Casting glass ceramic technology　　The bottom layer or all ceramic crown of composite porcelain crown is made by using traditional refractory material embedding wax mold, wax loss method ring less casting, and crystallization treatment processes to cast glass ceramics. Common cast glass ceramics can be roughly divided into two types: one is mainly composed of silica fluoromica, such as Dicor ceramics, and the other is mainly composed of apatite, such as Cerapearl ceramics, which have a bending strength of 125 MPa and a fracture toughness of 1.31 MPa. In addition to the aforementioned products, there are also domestically produced Liko glass ceramics, Plat ceramics, and Nissan Olympus ceramics. Among them, Liko ceramics belong to the K2O-Al2O3-MgO-SiO2-F system, with the main crystal phase being tetrafluoromica. Its physical and chemical properties are very similar to those of Dicor ceramics, with slightly lower strength than Dicor ceramics, but at a low price, it is very suitable for domestic promotion and use. The tensile strength of Plat ceramics is 145MPa, compressive strength is 250MPa, fracture strength is 165MPa, and elastic modulus is 93MPa, which basically meets clinical requirements. Olympus is currently the strongest among the reported cast ceramics, with a bending strength of 220-230MPa　　2. Hot pressed ceramics　　The basic composition of IPS Empress ceramics comes from feldspar ceramics, which are composed of 63% SiO2, 17.7% Al2O3, 11.2% K2O, 4.6% Na2O, 0.6% B2S3, 0.4% CeO2, 1.6% CaO, 0.7% BaO, 0.2% TiO2 by weight. The crystalline part of the ceramics is garnet crystals, with a content of 23.6-41.3%. The manufacturing process involves placing the restoration wax on a specially designed cylindrical furnace mold. Embed with phosphate embedding material and heat the model to 850 ℃. Open the top cover and place the porcelain block, cover it with aluminum oxide push rod, and press the automatic button. The furnace automatically heats to 1150 ℃ according to the given program and maintains it for 20 minutes. The viscous glass ceramic material is injected into the model under a pressure of 0.3-0.4 MPa, and the forming process of ceramic repair is completed. Subsequently, surface glaze porcelain with similar composition to the substrate material is used for coloring treatment, or the corresponding color is obtained through porcelain decoration technology. This technique has been widely applied in clinical practice due to its advantages of simplicity, time-saving, and low cost. The commonly used hot pressed ceramics include IPS Empress and OptecHSP. Due to the low strength of IPS Empress glass ceramic, which is only 133.5 ± 21.5MPa, it is currently limited to the production of inlays, veneers, and individual anterior crowns.　　3. Powder coated aluminum porcelain　　In ceram is a new type of powder coated all ceramic restoration high alumina ceramic product developed on the basis of Hi ceram, with an Al2O3 crystal content of over 99%. This technical method involves preparing high-purity Al2O3 powder into a high volume fraction slurry, coating it onto a specialized In Ceram refractory material mold, absorbing water through the capillary action of the mold to form a nucleus, and sintering it in an In Ceram furnace at 1100 ℃ for 2 hours to form a porous aluminum oxide framework with certain strength. Then, in the second process, a special component of glass material is coated and infiltrated at a high temperature of 1150 ℃. The glass material infiltrates between Al2O3 particles, As a result, cracks diffuse. The infiltration of glass material almost eliminates all pores, thus enhancing the bending strength. The experiment shows that the bending strength of In Ceram is about 10 times that of feldspar ceramics and 4 times that of glass ceramics, and its color is realistic with good suitability. The average edge lift is 39 μ m. Can be used to make all ceramic crowns and fixed bridges for anterior or posterior teeth. After glass infiltration, the alumina core is coated with Vita's specialized ceramic powder for surface decoration, resulting in an ideal restoration shape similar to natural teeth.　　4. Machinable ceramics　　There are currently four main types of machinable ceramics:　　(1) Feldspar machinable ceramics, such as VitaMark I and VitaMark II;　　(2) Feldspar ceramics with the main crystal phase being garnet crystals, such as ProCAD;　　(3) Machinable glass ceramics, among which mica based ceramics include Macor-M, DicorMGC, MGC-F (containing tetrasilicate mica), photogel (also containing zirconia), etc. Apatite based ceramics include Bioram-M;　　(4) Alumina ceramics, such as ProceraAllCeram and alumina glass composites.　　The first three types of ceramics are restoration bodies that are directly milled and cut into the required size using CAD/CAM technology, and then glazed and colored to complete the restoration production. Due to their bending strength generally below 150MPa and fracture toughness less than 2.0MPa, they are only recommended for inlays, veneers, and anterior crowns. Aluminum oxide ceramics, on the other hand, are made by milling and cutting the partially sintered porous aluminum oxide body into the base core of the restoration using CAD/CAM technology, and then undergoing glass infiltration treatment to improve its strength. The decorative ceramics are processed, and their strength is similar to that of In ceram, which can be used to make crowns and bridges.