Complete-crown and partial-coverage tooth preparation designs for bonded cast ceramic restorations

A new concept for tooth preparation design for complete- and partial-coverage all-ceramic restorations is presented. Because of the efficacy of third-generation dentinal bonding agents, the preparations for complete-coverage and partial-coverage restorations can be made with less emphasis on retentive form. For partial-coverage restorations, cavosurface angles should be large so that the resultant configuration of the enamel rods is conducive to optimal bonding. The new preparations are simple, with extremely tapered axial walls, to allow maximum thickness of the ceramic material. These types of preparations result in finished restorations that are stronger and have better margins and less chance of microleakage. Long-term success of these types of restorations will be determined by the success or failure of the dentinal bonding agent and resin cement system used.