Metal-ceramic systems represent a high-strength treatment associated with long-term success, but they have several disadvantages, mainly in terms of esthetics and biocompatibility. Over the past decade, a number of novel all-ceramic crown and bridge systems have been developed, with the capability of restoring anterior, posterior and multiple units. The search for new methods has been driven, in part, by patients,who have increasingly high expectations of esthetic dentistry and who also have concerns about the intraoral biocompatibility of metals.
Recent developments in dental materials have led to the introduction of a large number of all-ceramic systems for full-coverage restorations. Further improvements in high-strength all-ceramic technology have been achieved with the advent of computer-aided design and milling (CAD/CAM) systems.This type of all-ceramic crown resists fracture during function or parafunction, at both anterior and posterior sites, even under high stresses. The design and manufacture of these restorations involves optical scanning and digitizing of the dies (which are created from a master impression of the prepared teeth and cores), to precisely duplicate the margins of the tooth preparation. The scanned 3-dimensional images of the dies are then used to design the substructure, prompted by computer software (CAD). The CAD unit is linked to a robotic CAM centre, which creates a ceramic coping to the design specifications.
Zirconium oxide is a ceramic material that is used as the substructure (foundation) for making ceramic crowns and bridges
The advantages of this material compared to metal ceramic are:
Mr. R V Deshmukh
Wellness Coach,Aarogya Nutrition Centre - Retd Govt Officer