Restorative and occlusal strategies in implant-supported restorations for partial edentulism

OBJECTIVES The purpose of this study is to provide a narrative review of oc clusal principles applicable to im plant-supported restorations of partial edentulismbased on cur rently available data in the litera ture. The aim is to provide practi cal clinical recommendations on the occlusion management of im plant-supported restorations. MATERIALS AND METHODS The search was conducted using the PubMed/MEDLINE database. Inclusion criteria led to the analy sis of all selected material by the combination of the following key terms: ‘occlusion’ OR ‘implant overload’ AND ‘implant-supported restorations’ OR ‘implant-sup ported fixed partial dentures’ OR ‘implant-supportedprostheses’; ‘occlusal materials’ OR ‘prosthetic materials’ AND ‘implant-support ed restorations’ OR ‘implant-sup ported fixed partial dentures’ OR ‘implant-supported prostheses’. CONCLUSIONS Inclusion in the review was re served for articles, reviews andclinical studies on the manage ment of occlusion in implant-sup ported partial edentulous resto rations, with particular reference to overload, potentially occlu sion-related complications, con cepts, strategies and occlusal morphology of implant-supported restorations, and the choice of oc clusal material. In vitro studies and finite element analyses were included because they comple ment occlusion analysis with dif ferent methodologies and allow a better understanding of the bio mechanical principles involved. Publications on ‘full-arch’ im plant-supported rehabilitations, case reports and animal studies were excluded. Only articles in English were included. RESULTS Occlusion in implant-supported restorations is a debated topic and currently the occlusal concepts and strategies proposed in the lit erature are lacking in scientific evi dence. Recommendations and suggestions on the occlusion of implant-supported restorations are mainly based on expert opinion and intuitive guidelines without a high level of evidence. The differ ences between natural teeth and implants and the topic of occlusal overload, although the topic re mains controversial, form the basis for the management of occlusion in implant-supported restorations. The favorable prognosis ofim plant-supported prostheses is linked to a correct understanding of the biomechanical principles in volved. In this regard, simulation studies using finite element analy sis prove useful in designing occlu sal morphology aimed at minimiz ing overload onrestorations and supporting implants. The choice of occlusal material for restorations is mainly related to mechanical prop erties, aesthetics and the incidence of technical complications The biophysiological differences be tween implants and natural teeth have stimulated research on im plant occlusion and are the basis of occlusal concepts in implant pros thetics. However, there is limited ev idence-based consensus on how to manage occlusion in cases of im plant-supported restorations of par tial edentulism. Occlusal strategies involving changes in prosthetic de sign, occlusal morphology and the intensity and distribution of occlusal contacts represent a reasonable ap proach to distribute occlusal forces while minimizing unfavorable loads on the implant-prosthesis. Regard ing the choice of occlusal material, the introduction of monolithic zirco nia, due to its reliability and practi cality, has led to a reduction in the complexity of prosthetic design and represents a promising material.