Resin composite or ceramic inlays/onlays in posterior permanent teeth : a review of the literature

Abstract

Objective: To compare the clinical survival and long-term costs of extensive composite restorations to ceramic inlays and onlays. The hypothesis was that ceramic inlays and onlays can be more tooth substance saving and long-term economic for the patient than composite restorations. Methods: The dental literature, predominantly since 1990, was reviewed for prospective clinical studies of longevity of ceramic inlays/onlays and direct composite restorations in permanent posterior teeth. Only studies lasting at least 1,5 years and with 30 restorations at baseline were accepted, and retrospective studies, case studies and studies performed at universities were excluded. Results: A total of 20 studies met the established inclusion criteria. Failure rates varied from 4-30% in observation times of 1,5 years to 18 years for composite restorations, and from 0-19% during 2-10 years of follow-up for ceramic restorations. The most common reasons for failure were secondary caries (57%) for composite fillings and material fracture (64%) for ceramic inlays and onlays. The initial cost ratio of a typical 3-surface composite filling to that of a similar sized ceramic restoration was found to be 1:4,4. Conclusions: Bulk fracture and secondary caries are the main causes for failures of ceramic inlays/onlays and composite resin restorations, respectively. Oral hygiene, calibration methods and control of the patients drop out are important factors to be accounted for in long-term clinical trials. More RCTs and CCTs with solid study designs are still needed to evaluate the survival and costs of both composite restorations and ceramic inlays/onlays in posterior teeth.