Marginal integrity and postoperative sensitivity in Class 2 resin composite restorations in vivo

INTRODUCTION: Problems that may arise in resin composite Class 2 restorations include microleakage and postoperative sensitivity. However, limited in-vivo research is conducted to evaluate these processes. AIM: The aim of this study was to assess postoperative sensitivity, microleakage and the pooling of adhesives in relation to Class 2 box-type composite restorations placed in vivo using various adhesive systems and application techniques. MATERIALS AND METHODS: One hundred and forty-four Class 2 box restorations were placed in the mesial and distal surfaces of 72 premolar teeth in-vivo using one of three combinations of adhesive systems and three filling techniques. After 6 weeks of clinical service postoperative sensitivity was recorded. The teeth were then extracted, immersed in a dye solution and sectioned. Microleakage and pooling of the adhesive was recorded. Statistical analysis involved logistic regression and chi2 tests to identify differences between groups at p < 0.05. RESULTS: Of the 144 restorations, 65 showed minimal cervical leakage in enamel, 5 suffered leakage into dentin and 74 were free of microleakage. No statistically significant differences were found in cervical microleakage between the adhesive systems or between filling procedures. Occlusal microleakage in the enamel was present in 16 of the 160 restorations. Liner Bond 2 restorations leaked significantly more at the occlusal surface (p < 0.05). Pooling of the adhesive was significantly less when PhotoBond was used. No spontaneous postoperative sensitivity was reported. Twenty-eight restorations were sensitive to loading. Postoperative sensitivity was significantly less in patients with Liner Bond 2 restorations. CONCLUSIONS: The adhesive systems used in this study showed minimal leakage into dentin in vivo. Using Liner Bond 2, restorations exhibited more occlusal leakage but were significantly less sensitive to loading.