Effect of accelerated restorative techniques on the microleakage of class II composites

PURPOSE: To assess the marginal seal of Class II resin-based composite restorations cured by a high intensity halogen light or a plasma arc light. MATERIALS AND METHODS: Class II cavities were prepared in extracted molar teeth with cervical margins located apical to the cemento-enamel junction. Cavities were restored with a posterior resin-based composite (Tetric Ceram) using either a two-increment or a bulk placement and cure restorative technique after application of bonding agent (Excite). Test parameters included light unit type/curing mode, application of flowable composite and restorative technique. After thermocycling, the teeth were immersed in basic fuchsin dye. Sectioned restorations were examined under a stereomicroscope (x 25) and extent of microleakage (mm) was recorded using an image analysis system. Data was analyzed by non-parametric statistical tests. RESULTS: No leakage was observed at the occlusal enamel margin of a nyrestoration. Median gingival leakage values for the different test groups ranged from 0.02-2.51 mm. Light unit type had a highly significant effect on leakage (P=0.0002). The highest leakage scores were recorded with the plasma arc light used in standard curing mode and the lowest with the halogen light in turbo-boost mode.