Is the clinical performance of composite resin restorations in posterior teeth similar if restored with incremental or bulk-filling techniques? A systematic review and meta-analysis.

Objectives: A systematic review was performed to analyze the clinical performance of class I and II restorations in posterior teeth placed with the incremental or the bulk-filling techniques. The primary outcome was retention/fracture rate, and the secondary outcomes evaluated were anatomical form, surface texture, color match, marginal adaption, marginal discoloration, caries, and postoperative sensitivity.
Methods: Electronic and manual searches were performed for randomized clinical trials comparing the clinical performance of composite resin restorations in posterior teeth placed with the incremental or the bulk-filling techniques. The Cochrane Collaboration risk of bias tool was used to assess the quality of the studies and the GRADE tool was used to access the quality of the evidence.
Results: Fourteen studies were included in this systematic review and most of them had unclear risk of bias. The risk difference (RD) for retention/fracture was 0.00 (95%CI =  - 0.01, 0.01; p = 0.86) for 1-1.5 years of follow-up; 0.00 (95%CI =  - 0.02, 0.02; p = 0.88) for 2-3 years of follow-up; 0.05 (95%CI =  - 0.08, 0.18; p = 0.46) for 5 or more years of follow-up. The RD for postoperative sensitivity was 0.04 (95%CI =  - 0.02, 0.10; p = 0.18) for up to 30 days; 0.00 (95%CI =  - 0.01, 0.02; p = 0.63) for 1-1.5 years of follow-up; and 0.00 (95%CI =  - 0.01, 0.02; p = 0.71) for 2-3 years of follow-up. For the other secondary outcomes, no significant differences were observed (p > 0.05) between the restorative techniques. The certainty of evidence was graded as moderate.
Conclusions: The clinical performance of class I and II restorations in posterior teeth is similar when placed with the incremental and bulk-filling techniques.
Clinical Relevance: Based on the results of this study, posterior restorations placed with bulk-filling technique present satisfactory clinical performance, which is similar to direct restorations placed with the conventional incremental technique, considering various follow-up periods evaluated.
Trial Registration:  CRD42018108450.
(© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)