Recent developments in materials and processes for ceramic crowns. Council on Dental Materials, Instruments, and Equipment.
Recently, a number of new materials and processes have been introduced for the construction of ceramic jacket crowns. These include new, stronger ceramics for reinforcing porcelain crowns. Also, processes have been developed for fabricating more accurately fitting ceramic crowns. Based on the strengths reported and clinical failure data with comparable materials, they may be suitable for anterior crowns as alternatives to porcelain-fused-to-metal crowns. Manufacturers' indications for use also include posterior crowns. Clinical data on their performance, however, have not yet been documented in published literature. Individual ceramic crowns offer a potential for a better esthetic appearance than porcelain-fused-to-metal crowns. The accepted marginal design indicated by manufacturers for ceramic jacket crowns is the 90 degrees full shoulder with a rounded gingival-axial line angle or a deep chamfer. Tooth reduction is 1.0 to 1.5 mm for axial surfaces and 1.5 to 2.0 mm for incisal edge or occlusal surfaces. Specific margin designs and other recommendations for tooth preparation should be followed for each of these materials. These new developments represent an addition of new materials and technology into an important area of restorative dentistry. As ceramic crowns have similar appearance, it is prudent for the dentist to seek evidence that the new high-strength ceramics are actually being used rather than the weaker conventional porcelains. Information on the clinical performances of the molded and cast ceramic crowns is not yet published. Their performances in long-term clinical situations have yet to be documented and published. The council will publish an update on ceramic crowns when additional information becomes available.
D000571:American Dental Association; D002516:Ceramics; D003442:Crowns; D003776:Dental Porcelain; D013674:Technology, Dental; D014481:United States
D003776:Dental Porcelain