Dental occlusion: modern concepts and their application in implant prosthodontics

The aim of this article was to review the literature on various aspects of occlusion related to implant prosthodontics, using PubMed and the Cochrane library. Even if the number of studies on implants and prosthodontics is very large, no randomized controlled trials or Cochrane reviews were found on the possible influence of occlusal design or characteristics of occlusion on treatment outcome. Therefore, studies and articles of a lower evidence level were accepted as the main part of the review. The widely spread opinion that implants are superior to natural teeth was refuted by two recent consensus conferences, which concluded that the long-term outcome of implant restorations is not better than that of natural teeth. No controlled studies on the optimal features of a harmonious natural and/or restored occlusion, including implant prostheses, were found. Nor was there any evidence that more sophisticated methods in jaw registration, e.g., using face-bows and adjustable articulators, compared with simpler methods, will yield better clinical prosthodontic results. This article discusses, among other things, concepts of occlusion of implant-supported restorations, occlusal material, cantilevers, and occlusal risk factors. Within the limitations of the review, it was concluded that many factors can influence implant failure and peri-implant bone loss but that little is known of the relative importance of such factors. Most probably, however, occlusal factors and details of occlusion are in general of minor importance for the outcome of implant restorations. Occlusion can be managed successfully by using simple methods for jaw registration and different occlusal concepts. This article is based on a lecture presented at the Asian Academy of Osseointegration, Hiroshima, Japan, July 18, 2008