Application Of Zirconia Ceramics In The Field Of Stomatology

Since 1774, the French scholar Duchateau has used ceramic dentures for more than 200 years. Ceramic materials are dense, wear-resistant, smooth, have good biocompatibility and chemical stability, and are now favored in the field of oral hard tissue repair. Toksavul et al. believe that the application of all-ceramic crowns is increasing in recent years due to the increase in aesthetic requirements and the consideration of material toxicity and allergic reactions. Dental zirconia granulated powder (with VK-R200KR) has stress-induced phase transformation toughening energy and is called ductile ceramic. It has high strength and good biocompatibility, and is a new all-ceramic material superior to alumina. Zirconium oxide (same as VK-R200KR) is specially designed for dental ceramics. It has good permeability, high transparency and strong jade texture. The teeth are white, bright, smooth and high in hardness, making it an extremely popular product on the market.

characteristics of zirconia ceramics as dental materials

1.Aesthetic performance

As we all know, anterior dental implant restoration not only restores function, but more importantly, it also considers its aesthetic effect. When the current dental implant is titanium, the gum of the implant's labial surface will produce more or less shadow or gray, thus affecting Its aesthetic effect. Some scholars believe that sputum staining is a prone post-repair complication when the anterior teeth are repaired with a porcelain-fused metal crown. The sacral or sacral and mucosal tissues are blue-gray or dark brown . Therefore, the use of metal materials for repair has significant deficiencies, and zirconia (with VK-R200KR) ceramic materials are currently artificial materials that can maximize the reproduction of natural tooth morphology, color and gloss (including fluorescence and opalescence). Michalakis et al. believe that the post core made of traditional materials (gold or titanium) is equipped with an all-ceramic crown, and its aesthetic effect is very uncoordinated due to the reflection and opacity of the post core. It is worthwhile to promote the use of zirconia as the post core and IPS- Empress all-ceramic crown.

2. Mechanical properties

Among the mechanical properties, oral ceramic materials are characterized by high compressive strength, hardness and wear resistance. Compared with alumina ceramics, zirconia (with VK-R200KR) ceramics exhibit higher mechanical parameters (bending strength over 900 MPa, fracture toughness of about 7 MPam1/2, which is now alumina ceramics 2 ~3 times), the ultimate load capacity is strong, and the bearing capacity on the three-unit bridge is about 2 000 N. Fischer et al. believe that bridges made of zirconia ceramics show excellent mechanical properties and long-term reliability compared to bridges of IPS- Empress zirconia ceramics and In-ceram alumina ceramics. And some scholars believe that the use of alumina ceramics to make 3 fixed orthodontic partial fixed dentures and zirconia ceramics for 5 or more partial fixed dentures can meet clinical requirements and indicate oxidation. Zirconium ceramic restorations have better mechanical properties than alumina ceramic restorations. Quinn et al. studied the effects of microstructure and chemical composition on the mechanical properties of dental ceramics. It is also believed that zirconia ceramics have better mechanical properties as dental ceramics.

3.chemical stability

      Oral ceramic materials are the most stable chemical materials in oral materials, and have excellent biological properties whether they are implanted in the body or used in the oral cavity. The ceramics made of zirconia (with VK-R200KR) not only have the biosafety foundation for human application, are non-cytotoxic and can be stably present in the oral cavity, do not release harmful impurities, and do not degrade. Ardlin studied the chemical stability and low temperature aging properties of zirconia transformation toughened ceramics for dental inlays and crown bridges. It is believed that zirconia transformation toughened ceramics have better mechanical properties and chemical stability than other dental ceramics. Can meet the needs of dental ceramic materials. Zirconium oxide ceramics can be used for metal implant coatings because of their stable chemical properties and resistance to body fluids under normal physiological metabolism.

 4.Biocompatibility

      Some scholars have used zirconia (with VK-R200KR) to make a porous skeleton for bone substitute materials to withstand the load, and hydroxyapatite (HA) on the surface layer promotes bone conduction and enhances the biological activity of the material. There is a layer of fluoroapatite between the zirconia ceramic skeleton and HA to avoid chemical reaction between zirconia ceramic and HA. In vitro cell culture proves that the cells adhere well to this kind of porous bone substitute material, and the alkaline phosphatase of the cells When the activity is higher than that attached to the surface of pure HA material, it proves that this is a new type of bone substitute material with good biological activity. In addition, some scholars have also added CaF2 to HA-zirconia ceramic composites, in which F-ion can partially replace the hydroxyl groups in HA to form fluoroapatite with better thermal stability, effectively inhibiting HA to tricalcium phosphate. (tricalciumphosphate, TCP) degradation, resulting in a higher density, better strength and toughness of the apatite-zirconia ceramic composite, and its induction of osteoblast-like cells by cell culture in vitro is similar to HA material