CLASS-5 COMPOSITE RESIN RESTORATIONS - MARGIN CONFIGURATIONS AND THE DISTANCE FROM THE CEJ

An in vitro study of 60 teeth examined the cervical microleakage of cl ass 5 composite resin restorations in regard to preparation design and location from the cementoenamel junction (CEJ). Four groups of 15 tee th each were prepared for a class 5 composite resin restoration with t he cervical margins finished as follows: a butt joint margin placed le ss than 1 mm from the CEJ, a beveled margin placed less than 1 mm from the CEJ, a butt joint placed greater than 1.5 mm from the CEJ, and a beveled margin placed greater than 1.5 mm from the CEJ. The teeth were acid etched, treated with an enamel bonding agent, and restored with a microfilled composite resin, and then sectioned for further analysis . The sectioned specimens were evaluated for cervical microleakage by Ca-45 autoradiography. The butt joint margins placed less than 1 mm fr om the CEJ had significantly more microleakage than the other groups, indicating that all enamel margins of a class 5 composite resin restor ation should be beveled to decrease microleakage regardless of their l ocation relative to the cementoenamal junction.