Microleakage around glass-ceramic insert restorations luted with a high-viscous or flowable composite.

PURPOSE The purpose of this study was to evaluate microleakage around Class V resin restorations restored with glass-ceramic inserts luted with a high-viscous composite resin or a flowable composite resin. MATERIALS AND METHODS Twenty extracted human premolars (patient age range 12-18 yr) were randomly assigned to four groups. Class V preparations in two groups were filled using a glass-ceramic insert (Megafiller Standardformen, Hager Werken GmbH, Duisburg, Germany) luted with either a hybrid, high-viscous composite (Tetric, Ivoclar Vivadent, Schaan, Liechtenstein) and a bonding agent (Excite, Ivoclar Vivadent) or a flowable composite (Crystal-Essence, Confi-Dental, Louisville, CO, USA) and a bonding agent (Confi-Quick, Confi-Dental). Two groups without inserts served as controls and were bulk filled with either a hybrid, high-viscous composite (Tetric) or a flowable composite (Crystal-Essence). The preparations were made with a no. 330 tungsten carbide fissure bur (Komet, Lemgo, Germany) in a water-cooled, high-speed handpiece with a mesiodistal width of 3 mm, an occlusogingival height of 3 mm, and a depth of 2 mm. All margins had butt joints. The teeth were thermocycled for 24 hours in water baths held at 5 degrees C and 55 degrees C, and the specimens were prepared and examined for microleakage using basic fuchsin as a marker. Relative leakage was recorded according to the extent of dye penetration on a scale of 0 to 4, with 0 indicating no dye penetration and 4 indicating that dye penetration had progressed as far as the cavity floor. The results were analyzed using the Kruskal-Wallis test (nonparametric analysis of variance) and Dunn's multiple comparisons test (p < .05). RESULTS There was no significant difference in microleakage around inserts luted with a high-viscous composite occlusally (p = .7563) or gingivally (p = .6187) and around cavities bulk filled with the high-viscous composite. There was a significant difference in microleakage around inserts luted with a flowable composite both occlusally (p = .0345) and gingivally (p = .0285) and around cavities bulk filled with the flowable composite. Inserts luted with the flowable composite showed significantly less microleakage than those cemented with the high-viscous material only at the gingival margins (p = .0345). Comparisons of microleakage around the high-viscous and flowable composites showed no significant difference in microleakage at either the occlusal or gingival margins (Dunn's multiple comparisons test p > .5 in all cases). CLINICAL SIGNIFICANCE In Class V preparations of the size cut in the present study, ceramic inserts are shown to be of value in reducing microleakage when compared with bulk filling with flowable composites. Microleakage was not significantly improved by using a ceramic insert with a viscous composite compared with the viscous composite alone.