Composite resin or ceramic inlays, onlays, and overlays can achieve high long-term survival and success rates.
This study evaluated the long-term clinical performance and complications of composite resin or ceramic inlays, onlays, and overlays, as well as identified the factors that might influence the clinical outcome of the restorations.
A systematic literature search was conducted in the Pubmed, Embase, Cochrane Central Register of Controlled Trials, and Web of Science databases until April 30, 2019, without language restrictions. Randomized clinical trials, clinical retrospective, and prospective cohort studies with a mean follow-up period of five years were included. Two reviewers extracted the study data independently. Newcastle-Ottawa Scale was applied for quality assessment. Meta-analysis was performed by the random-effects model and fixed-effects model.
After removal of duplicates, 2818 studies were identified. Finally, 13 observational studies were included in the meta-analysis based on retrospective and prospective cohort studies. The cumulative survival rate and success rate of composite resin inlays, onlays, and overlays were 91% and 84% after five years of follow-up, respectively. The survival rates of ceramic inlays and onlays were 90% at 5 years, 89% at 8 years and 85% at 10 years, while the success rates of ceramic inlays and onlays were 88% at 5 years and 77% at 10 years. Secondary caries and endodontic complications were the predominant failures for composite resin inlays, onlays, and overlays, while restoration fractures and endodontic complications were the main failures for ceramic inlays and onlays. No direct association between parafuntional habits and bruxism and the fractures of restorations was found. Nonvital teeth and multiple-surface restorations tended to increase the risk of failure. Regarding other factors influencing the clinical outcome, no definite conclusion could be drawn due to inconsistent results.
The long-term clinical outcomes have been demonstrated to achieve high survival and success rates based on 10-year data for ceramic inlays and onlays, as well as 5-year data for resin inlays, onlays, and overlays.