Glass hybrid versus composite for non-carious cervical lesions: Survival, restoration quality and costs in randomized controlled trial after 3 years

Objective: This study compared survival, restoration quality and costs of glass hybrid (GH; EQUIA Forte Fil/ EQUIA Forte Coat) and resin composite restorations (RC; OptiBond FL/Filtek Supreme XTE) of sclerotic noncarious cervical lesions. Methods: This is a cluster-randomized trial (ClinicalTrials.gov: NCT02631161). 88 patients (50-70 years) with 175 sNCCLs were randomized to receive GH or RC. Restorations were placed without mechanical cavity preparation and followed for a mean 36 (min/max: 31/55) months (variable follow-up due to COVID-19 lockdown). Restoration quality was re-evaluated at 1-, 18- and 36-months using FDI-criteria. Survival was assessed using multi-level Cox-regression analysis. Costs were estimated from a payer's perspective in Germany. Initial costs were determined based on micro-costing using time recordings and hourly costs, and follow-up costs based on statutory insurance fee-item-catalogues. Results: 88 patients (175 restorations) were treated; 43 received GH (83 restorations), 45 RC (92 restorations). 17 GH and 19 RC showed total retention loss, 5 GH were partially lost (p = 0.396/Cox). FDI ratings were not sufficiently different for any domain except surface luster, where RC showed higher score (p < 0.001). Costs were initially lower for GH (32.57; SD 16.36 & euro;) than RC (44.25; SD 21.40 & euro;), while re-treatment costs were similar (GH: 9.15; SD 15.70 & euro;; RC: 7.35; SD 14.51 & euro;), resulting in significantly lower costs for GH (GH: 41.72; SD 25.08 & euro;) than RC (51.60; 26.17 & euro;) (p < 0.001/GLM). Conclusions: While survival was not significantly different, GH was significantly less costly both initially and longterm than RC for restoring non-carious cervical lesions. Clinical significance: Within this trial, survival was not significantly different between GH and RC to restore sclerotic NCCLs. As GH was significantly less costly both initially and long-term than RC, using RC was only costeffective for payers willing to invest high additional expenses per minimal survival gains.