Evaluation of Microleakage in Class II Bulk-fill Resin Composite Restorations

Abstract

Objective: The aim of this study was to evaluate the microleakage of class II resin composite restorations applied by bulk fill technique, and to  compare the results with the incremental technique.

Materials and Methods: Sixty box-only class II cavities (5x3x2mm) were prepared in extracted non-carious human molars with gingival margin in the enamel. The teeth were restored with 4 different materials  and assigned into four groups (n=15): group1 Filtek Bulk-Fill, group 2   X-tra fil Bulk-Fill group 3 SonicFill (bulk fill technique), and control group  Tetric Evo Ceram (incremental technique). After thermocycling, the specimens were immersed in Pelikan ink 4001 blue dye solution and incubated at room temperature for 24 hours. The teeth were subsequently sectioned mesiodistally. All specimens were examined at 50× in a stereomicroscope. Dye penetration was measured from occlusal and gingival margins. Data were statistically analyzed using the Kruskal Wallis, Wilcoxon, and Mann – Whitney U tests (P < 0.05).

Results: No significant differences in dye penetration were found between the control and the experimental groups, and among occlusal and gingival margins. But microleakage scores were higher in gingival margins compared with oclussal margins. Bulk-fill technique group SonicFill showed less microlekeage scores.

Conclusions: Within the experimental conditions of this in vitro study, None of the restorative techniques tested completely eliminated microleakage dye penetration in oclussal and gingival margins; Viscosity of the bulk fill restorative material influenced the microlekeage and the internal adaptation.

Keywords: Microleakage, Resin Composite, Bulk-fill, sonic.