Clinical performance of low-shrinkage giomer compared to nanohybrid resin composite in proximal restorations after one year: a randomized clinical trial

OBJECTIVES: The present study assesses the clinical performance and occlusal wear of low-shrinkage giomer and nanohybrid composite in proximal restorations. METHODS: Fifty participants with proximal caries in posterior teeth (n = 25) were recruited. Teeth were restored with either conventional nano-hybrid composite (Filtek Z250XT, 3M ESPE, USA) or low-shrinkage giomer (Beautifil II LS, Shofu Inc, Japan). Clinical performance was assessed using revised FDI criteria at baseline, 6 and 12 months. Wear was assessed after 12 months by using 3D inspection and metrology software (Geomagic Control X; 3D Systems, USA). FDI scores were analyzed using Chi‑square test for intergroup comparisons and Cochran's Q‑test for intragroup comparisons. Wear data were analyzed using independent t test for intergroup comparison and paired t test for intragroup comparisons. RESULTS: At the 12-month follow-up, both Beautifil II LS and Filtek Z250XT exhibited high clinical success rates, with 100% and 96% success rates, respectively. Beautifil II LS restorations had a 4% lower risk of failure compared to Filtek Z250XT (ARR = 4.0 (95% CI -12.6 to 19.5, P > 0.05)). The mean wear after 12 months was 0.036 ± 0.01 mm for Beautifil II LS and 0.038 ± 0.01 mm for Filtek Z250XT. The difference between groups was minimal (0.0026 mm; 95% CI: -0.0271 to 0.0324) and not statistically significant (P = 0.8178). CONCLUSION: Low-shrinkage giomer showed satisfactory clinical performance and wear resistance compared to nanohybrid resin composite after one year. Both materials are considered clinically acceptable as per the American Dental Association (ADA) standards.