On form and function in all-ceramic restorations.
All-ceramic restorations are achieving increasing popularity, partly because of the aesthetic demands of patients, but also because their increasing ease of fabrication and longevity compare favourably with the traditional plastic restorations in posterior teeth. The parallel development of cementation materials and bonding techniques has also improved longevity, although current evidence shows that posterior all-ceramic restorations have a slightly lower success rate than in anteriors, and the success rate falls with time. The purpose of this paper is to briefly review the evidence for the use of all-ceramic restorations particularly for posterior restorations on teeth, as well as to suggest that preparation form may need to change to take into account the properties of dental ceramics. In addition, a different approach to occlusal form is proposed, based on the evolution of form and function in dentitions, to suggest that the perfect reproduction of cusps and fissures may not be appropriate.