Glass Hybrid Versus Composite for Restoration of Non-carious Cervical Lesions

Objectives: We aimed to compare the survival of glass hybrid (GH; Equia Forte Fil/Equia Forte Coat (GC)) versus adhesive/nano-hybrid composite restorations (RC; OptiBond FL (Kerr)/Filtek Supreme XTE (3M)) of sclerotic non-carious cervical lesions (sNCCL). We further compared treatment times.
Methods: A 36-months cluster-randomized controlled trial was performed (ClinicalTrials.gov Identifier: NCT02631161); this is an interim analysis of this trial. The unit of randomization (cluster) was the patient; we accounted for clustering during our analysis. 88 patients (50-70 years) with 175 sNCCLs were randomized to receive GH or RC. Restorations were placed without previous mechanical tooth preparation by two calibrated operators, and the treatment time was recorded. Restoration performance was evaluated using FDI-criteria by one of two blinded, calibrated examiners. Our primary outcome, restoration failure (FDI code ≥ 4), was assessed using multi-level Cox-regression. Treatment time was evaluated using generalized linear mixed modelling.
Results: Treatment time was significantly shorter for GH (mean±SD: 11±6 min) than RC (14±6 min; p=0.012), and also differed significantly between operators (p=0.004). After mean 18 (min/max: 8/25) months, 78 patients (160 restorations) could be followed up. 15 (19%) restoration failures in 11 patients occurred in the GH-, and 11 (14%) restoration failures in 8 patients in the RC-group. In both groups the most common reason for failure was retention loss. Failure did not significantly differ between restorative materials (p=0.904/Cox). Higher age of patients (HR (95% CI): 1.16 (1.01-1.24) per year) and location of the restoration in the mandible (2.89 (1.00-8.31)) were associated with an increased risk of failure.
Conclusions: Restoration of sNCCLs with GH required less treatment time than RC, while the survival of both materials was not significantly different. GH may be a suitable alternative to RC for restoring sNCCLs.