Three-year clinical performance of direct restorations using low-shrinkage Giomer vs. nano-hybrid resin composite

Objectives The objective of this investigation was to compare the clinical performance of a nano-hybrid resin composite and a low-shrinkage Giomer resin composite.Material and methods In total, 35 pairs of restorations were performed using either low-shrinkage Giomer (Beautifil II LS, Shofu Inc.) or nano-hybrid (Clearfil Majesty Posterior) resin composite in 35 patients by two operators using the relevant adhesives, i.e., FL-Bond II (Shofu Inc.) and Clearfil SE Bond (Kuraray), with the self-etching technique according to each manufacturer's instructions. Two clinicians assessed the restorations 2 weeks (baseline); 6 months; and 1, 2, and 3 years after the restorative procedures using FDI (World Dental Federation) criteria (Scores 1-5). Data were analyzed using the marginal homogeneity and McNemar tests. The survival rate was calculated using Kaplan-Meier survival analysis and the survival of the two groups was compared with the log-rank test (p = 0.05).Results The mean observation period was 37.7 +/- 6.8 months. All restorations completed their 3-year follow-up. The criteria were mainly rated with high (1 or 2) scores for quality in both groups. Only one restoration in the low-shrinkage Giomer resin composite group was accepted as a failure at the 2-year recall due to retention loss.Conclusion At the 3-year follow-up, the performance of the restorations using the Giomer and the nano-hybrid resin composite were similar and clinically acceptable.Clinical relevance The low-shrinkage Giomer resin composite exhibited a similar clinical performance to the nano-hybrid resin composite after 3 years in service with both materials displaying minor surface deteriorations at the 3-year recall.Clinical Trial Registration https://clinicaltrials.gov, identifier: NCT02823769.