A Comparative Evaluation of the Postoperative Sensitivity of Bulk-Fill Versus Conventional Resin Class II Composite...

Introduction Postoperative sensitivity can be a prevalent issue in class II composite restorations, which may impact patient satisfaction levels. This prospective observational study aimed to compare the postoperative sensitivity of bulk-fill and conventional resin composites in class II restorations over one month. Methods Sixty-two patients with moderate-depth class II carious lesions in posterior teeth were consecutively enrolled. Restorations were performed using either a bulk-fill composite (Tetric EvoCeram Bulk Fill, Ivoclar Vivadent AG, Schaan, Liechtenstein) in a single 4-mm increment or a conventional composite (Filtek Supreme XTE, 3M ESPE, St. Paul, MN, USA) in 2-mm oblique increments, based on clinician judgment. The same universal adhesive and standardized operative protocol were used in both groups. Postoperative sensitivity was assessed using a Visual Analog Scale in response to thermal and occlusal stimuli at 24 h, one week, and one month. Clinical outcomes including restoration fractures, marginal gaps, and secondary caries were evaluated. Baseline characteristics were compared using independent t-tests and chi-square tests. Sensitivity scores were analyzed using Mann-Whitney U tests and a mixed-effects model. Results Both groups were comparable in terms of age, cavity depth, sex, and tooth type. Median sensitivity scores were similar at 24 h and one month, but significantly lower in the bulk-fill group at one week. The mixed-effects model revealed a significant main effect of material, with overall lower sensitivity in the bulk-fill group and a significant reduction over time in both groups without an interaction effect. The quantitative analysis indicated a reduced incidence of restoration fractures, marginal discrepancies, and secondary caries within the bulk-fill cohort; however, these differences did not reach statistical significance. Conclusion Bulk-fill composite restorations exhibited a markedly reduced overall postoperative sensitivity in comparison to traditional composites in class II cavities, notably observable at the one-week mark, while also demonstrating similar short-term clinical efficacy.