The Future of Dental Prosthetics: Advantages of Zirconia Blocks

Zirconia blocks are white crystals with high melting point and high hardness, and has good chemical stability and wear resistance. Zirconia blocks are usually insoluble in water and most common inorganic solvents, but can react with some acids or bases under some extreme conditions. The chemical properties of zirconia blocks are mainly reflected in their chemical reactions with other compounds.  As a tough, wear-resistant and fire-resistant material, they are widely used in various fields such as industry and medicine. Besides, Zirconia Blocks are favored by dental restoration clinicians due to their excellent mechanical properties, excellent biocompatibility and aesthetics. Now dental zirconia blocks are widely used in clinical practice, especially in posterior tooth full crown and fixed bridge restorations.

Strength and Durability

Zirconia blocks have extremely high strength, which is mainly due to the compactness of their internal structure and the fineness of their grains. This material can withstand great forces. During long-term use, zirconia blocks can maintain good surface morphology and dimensional accuracy, and are not prone to wear and deformation. In addition, zirconia has excellent high-temperature stability and can maintain its physical and chemical properties unchanged in high-temperature environments.

Aesthetic Appeal

Because the inner crown edge of the traditional nickel-chromium alloy restoration is placed in the patient's gingival sulcus and can be exposed to saliva and gingival sulcus fluid, it is very easy to corrode and cause gingival staining. During long-term use, the traditional cement dissolves and causes secondary caries, which not only affects the aesthetic restoration effect of the anterior teeth, but also causes tooth pulp-related inflammation, affecting the service life of the restoration. In severe cases, it can cause the root of the abutment to break, cause bite force disorders, and even lose chewing function. Zirconia blocks restorations have ideal light transmittance and good gloss. Their color and transparency are closer to natural teeth, and they are suitable for aesthetic restoration of the anterior teeth. The metals and alloys used in the past will appear dark black, and it is difficult to apply a shading layer on them to achieve better aesthetics. According to the patient's individual characteristics, the Zirconia blocks foundation piles can be ground out in a targeted manner. Appropriate appearance, and then suitable coloring and gum mucosa can further improve its aesthetic and harmonious effect. Moreover, the production of Zirconia blocks requires relatively high purity and good dispersion properties. Its particles are ultra-fine and the particle size distribution is narrow, which creates a perfect restoration shape and lifelike color, which can maximize the patient's aesthetic satisfaction. requirements. Researchers believe that effective treatment of the surface of ceramic restorations plays a very important role. Treatment of smooth porcelain surfaces can effectively improve the surface strength, which can increase patient comfort. In addition, it can also It can improve the accumulation of bacterial plaque and reduce the wear and tear on the jaw teeth. For its ceramic surface, choosing glazing as the repair material and carrying out related surface treatment can achieve significant aesthetic effects. Its luster is similar to that of natural teeth, and its aesthetics are high.

Biocompatibility

Zirconia blocks are biologically inert materials with excellent properties such as minimal adverse reactions, good cell adhesion, excellent tissue reactivity, less inflammatory infiltration, and high biocompatibility with surrounding bones and soft tissues. Various in vivo and in vitro studies have shown that zirconia has no cytotoxic effects on osteoblasts, fibroblasts, etc., and enables cells to modify the extracellular matrix by synthesizing various essential proteins and structural proteins. Studies have confirmed that there is a causal relationship between the accumulation of dental plaque on implants and inflammation of the mucosa around implants. Compared with metals, zirconia abutments have lower surface free energy and surface wettability, thus weakening the adhesion of bacteria and reducing the risk of diseases around implants. Zirconia ceramics are used in bone tissue replacement materials, oral post and core materials, crown and bridge repair materials, and implant materials to solve the problems of discoloration, corrosion, and allergies caused by metals. The results of the acute hemolysis experiment using fresh rabbit coagulation as the material showed that the hemolysis rate of zirconia blocks infiltration solution was less than 5%, which met the international general standards, indicating that zirconia ceramic materials are non-hemolytic.

Challenges

Ceramic materials have their corresponding brittleness, and porcelain chipping often occurs in clinical applications. Through a retrospective study of the clinical effects of zirconia blocks restorations, researchers found that compared with other reasons for failure, such as low occlusion, shedding, poor color matching, etc., porcelain chipping is the main reason for the failure of clinical zirconia blocks restorations, accounting for 86.2% of the total failure rate, and failures are mainly concentrated in the first 3 months after restoration. Therefore, the probability of porcelain chipping should be reduced in many ways.

Conclusion

Prosthodontics is an important treatment for tooth and edentulous defects. Various materials (such as ceramics, metals, polymer resin materials, etc.) are used to make and wear restorations, or to fix and implant them in the oral cavity, so as to achieve the purpose of restoring the structure and function of the oral cavity. This puts forward requirements on the physical and chemical properties of the restoration, such as mechanical properties and aesthetic properties, and the restoration must also have good biosafety. With the rapid development of dental restorative materials and people's pursuit of higher simulation of restorations, the use of all-ceramic restorations is increasing, among which zirconia blocks are widely used due to their excellent performance. Zirconia blocks have the advantages of restoring the chewing function of missing natural teeth, being able to adapt to the complex oral biological environment, and having no biological safety risks to the human body. At present, as one of the widely used materials in oral restoration, its effectiveness in oral fixed restoration has been fully recognized.