Up to 12 years clinical evaluation of 197 partial indirect restorations with deep margin elevation in the posterior region

Deep margin elevation (DME) relocates the cervical outline of large-sized cavity dimensions in the posterior area supragingivally, using a resin composite in a direct technique. The aim of this study is to evaluate the clinical performance of partial indirect restorations with DME and compare the effects of selected baseline variables on the (quality of) survival of the restorations. All teeth that were restored in combination with indirect restorations and DME between 2007 and 2016 were eligible for inclusion. Overall cumulative survival rates were calculated (Kaplan–Meier estimates) and compared among subsets of variables. Qualitative evaluation of all surviving restorations was performed using the modified United States Public Health Service (USPHS) criteria using Chi-square tests. A total of 197 indirect restorations in 120 patients could be included. Restorations or teeth presenting with secondary caries, fracture of the restoration/tooth, debonding of the indirect restoration, root caries, severe periodontal breakdown or pulpal necrosis were considered as absolute failures (n = 8) leading to an overall cumulative survival rate of 95.9% (SE 2.9%) up to 12 years, with an average evaluation time of 57.7 months. Some indication of degradation of the restorations was seen over time. Indirect composite restorations showed more degradation compared to ceramic restorations (p = 0.000). More wear of the antagonist was observed when teeth were opposed to ceramic restorations (p = 0.04). Endodontic treatment negatively impacted the occurrence of fracture of restorations and teeth (p = 0.000). Indirect restorations with DME have a good survival rate in this study, however longer follow-up is needed as degradation of the restorations is seen over time. This long-term study shows the possible clinical applicability of deep margin elevation.