ABSTRACT
In dental care, treating anterior dentition esthetically has always been difficult. Numerous restorative solutions, including resin composites, all-ceramic crowns, and ceramic veneers, become accessible with the advancement of dental materials. In such situations, practitioners and patients should pick the most appropriate option to enhance oral health and aesthetic outcomes. Any substance made of non-metallic inorganic matter and fired at an elevated temperature is referred to as ceramics (pyrochemical process). Ceramics called glass ceramics are those that commence in a glassy phase and later devitrify to a partly or wholly crystalline form. Dental ceramics that most closely optically resemble the characteristics of real teeth are primarily glassy materials, which are derived primarily from triaxial porcelain compositions of feldspar, quartz, and kaolin. Glass-ceramics possess much more toughness and strength than porcelain but are also less translucent. Tougher and more durable ceramics, primarily yttrium stabilized tetragonal zirconia polycrystals, have been developed recently (Y-TZP). Due to its limited translucency, Y-TZP presents a major drawback. A significant amount of current tooth structure must be removed in order to allow for a porcelain veneer that is wide enough to overlay an opaque zirconia base and replicate the optical characteristics of the surrounding natural teeth. Ceramic restoration effectiveness, in the end, relies on the material choice, production process, and restoration strategy.
ABSTRACT
The most widely used glass-ceramic is lithium disilicate (LD) because of its remarkable optical qualities, high strength, and simplicity of manufacture. Greater marginal strength, reduced porosity, and net-shaped manufacturing by pressing are further benefits of LD. The development of yttrium stabilized trigonal zirconia polycrystalline (Y-TZP) ceramics is the result of the pursuit for a material with both mechanical capabilities, like the resistance provided by metallic restoration, and the distinctive optical characteristics of glass-ceramic. The main drawback is the fragile veneering ceramics, which are prone to chipping, debonding, and breakage. There is evidence that extrinsic variables such beverages, mouthwashes, acid solutions, dental brushing, and increased temperatures might cause ceramic surfaces to deteriorate. The composition and surface shape of ceramic materials have an impact on the extrinsic pigment absorption or adsorption from the oral cavity. The main causes for the clinical replacement of anterior restorations, according to prior research, are poor color matching and color instabilities. Monolithic zirconia is more prone to staining from chlorhexidine, green tea, and coffee. In monolithic zirconia, the aging-related color changes are more pronounced. The color of the background substructure influences how zirconia restorations look overall. In terms of color stability and translucency, LD ceramic has also been proven to be more aesthetically pleasing. In comparison to monolithic zirconia, bilayer zirconia with feldspar veneering ceramic displayed reduced discoloration overall. It has been noted that monolithic zirconia is more susceptible to low-temperature degradation than the core Y-TZP. The use of current literature to infer outcomes has several limitations because in most vitro investigations, thermocycling has been carried out in water rather than oral cavity saliva and the influence of sunlight exposure, salivary proteins, food coloring, tobacco, different enzymes, and surface-related factors on the color stability is yet to be examined.