Three-year Randomized Prospective Clinical Trial of Class II Restorations Using Flowable Bulk-fill Resin Composites.

OBJECTIVES: This randomized, prospective, and split-mouth study aimed to evaluate flowable bulk-fill resin composites in class II restorations and to compare with a conventional layering technique after a 3-year follow-up. METHODS AND MATERIALS: Fifty-three subjects received three class II restorations according to the restorative systems: conventional microhybrid resin composite (PA, Peak Universal + Amelogen Plus, Ultradent), flowable bulk-fill and nanoparticulate resin composites (ABF, Adper Single Bond 2 + Filtek Bulk Fill Flow + Filtek Z350XT, 3M Oral Care), and flowable bulk-fill and microhybrid resin composites (XST, XP Bond + SDR + TPH3, Dentsply). The clinical performance and interproximal contacts were evaluated. Statistical analyses were performed using the equality test of two proportions, Logistic regression analysis, Friedman, Wilcoxon, Kruskal-Wallis, and Mann-Whitney tests (a=0.05). RESULTS: Forty-seven patients were evaluated at 3 years. XST bulk-fill restorative system presented higher marginal discoloration than PA, and the opposite occurred for surface staining. All restorative systems resulted in decreased interproximal contacts, occurring early for XST. CONCLUSIONS: Although the restorative system using incremental technique presented better performance for marginal discoloration, one of the restorative systems that used flowable bulk-fill resin composite (XST) showed the lowest surface staining. All restorative systems had decreased proximal contact over time.

Randomized Prospective Clinical Trial of Class II Restorations Using Low-shrinkage Flowable Resin Composite.

PURPOSE: The aim of this prospective, randomized, split-mouth clinical trial was to evaluate postoperative sensitivity, clinical performance, and interproximal contacts after using different restorative systems. METHODS AND MATERIALS: Fifty-three subjects each received three class II restorations according to the restorative systems: conventional resin composite (PA: Peak Universal+Amelogen Plus, Ultradent), low-shrinkage flowable and nanoparticulate resin composites (ABF: Adper Single Bond 2+Filtek Bulk Fill Flow+Filtek Z350XT, 3M ESPE), and low-shrinkage flowable and microhybrid resin composites (XST: XP Bond+SDR+TPH3, Dentsply). Postoperative sensitivity was assessed at 24 hours, seven days, 90 days, and six months. The clinical performance and interproximal contacts were evaluated at baseline, six months, and one year. Friedman, Wilcoxon, Kruskal-Wallis, and Mann-Whitney tests were used to evaluate postoperative sensitivity and interproximal contacts. The equality test of two proportions and logistic regression analysis were used to assess the clinical performance. RESULTS: No statistically significant differences were observed among groups for postoperative sensitivity. The highest spontaneous sensitivity was reported at 24 hours. ABF was the only group that did not present a reduction in cold sensitivity. Color, marginal discoloration, and superficial staining showed differences among the groups. XST did not show superficial staining after one year. No differences were observed among groups in relation to interproximal contacts. XST resulted in the loss of interproximal contact after one year. CONCLUSIONS: Different types of restorative systems do not influence postoperative sensitivity; however, ABF maintained cold sensitivity over time. Marginal discoloration occurred for all groups but occurred earliest for PA. XST presented a reduction of interproximal contact after one year of evaluation.