Influence of Operative Techniques on Clinical and Laboratory Outcomes in Class II Resin-Based Composite Restorations: A Systematic Review

Background:Operative technique is a major determinant of the long-term success of Class II resin-based composite restorations.Variations in adhesive strategy, layering approach, matrix system, and curing protocol influence marginal integrity, polymerization stress, postoperative sensitivity, and secondary caries.Because resin-based composite placement is technique-sensitive, synthesizing evidence on how specific operative steps affect outcomes is essential.This systematic review evaluated the influence of operative techniques on the clinical and laboratory performance of Class II resin-based composite restorations. Material/Methods:A comprehensive search of PubMed, Cochrane Library, and Embase identified 57 records.After duplicate removal and screening, 21 studies were included (11 randomized controlled trials and 10 in vitro investigations).Techniques assessed were adhesive protocols, layering strategies, matrix systems, and curing methods.Data extraction focused on restoration longevity, marginal adaptation, postoperative sensitivity, and secondary caries.Risk of bias was evaluated using the Cochrane tool for randomized trials and modified CONSORT/Joanna Briggs Institute criteria for in vitro studies.Meta-analysis was not feasible because of heterogeneity. Results:Multi-step adhesive approaches showed the highest 5-year survival (up to 91%) and lower secondary caries rates.Incremental layering reduced postoperative sensitivity and improved marginal adaptation.Sectional matrices produced tighter proximal contacts (76% vs 42%), while soft-start curing reduced marginal gap formation (112 m to 45 m).One-step adhesives and uncontrolled bulk-fill placement showed higher failure and hypersensitivity. Conclusions:Multi-step adhesives, incremental layering, sectional matrices, and soft-start curing provide the most favorable outcomes and support technique standardization in clinical practice.