SEM Evaluation and Microleakage of Direct and Indirect Composite Inlays

Objective:This study aimed to evaluate the microleakage of direct and indirect composite inlays by scanning electron microscopic analysis. Methods:Thirty bovine incisors were selected and ground to get an incisor platform, simulating a human molar. Each tooth received two proximal cavities with cervical margins prepared in dentine or enamel. One of the cavities was filled with Z250 + Single Bond, direct technique, and the other one with Solidex, Rely X + Single Bond, indirect technique. The samples were stored in deionized water at 37ºC for 24 hours and after that, placed in 50 wt% silver nitrate aqueous solution for 6 hours in a dark container. Then the samples were washed under running water, immersed in a developing solution and exposed to fluorescent light for 12 hours. The teeth were severed mesio-distally and evaluated for dye penetration by scanning electron microscope. Results:The results were obtained by the percentage of the penetration of the silver nitrate: TDE=9.0(3.42)A, TIE=7.79(2.78)A, TID=21.0(4.2)B, TDD=31.5(7.31)C. Data had been analyzed by Anova and Duncan test (p<0.05). Conclusions: There were no significant differences between the direct and the indirect technique with cervical margin in enamel, but in the dentin one, the indirect technique showed less microleakage than direct composite restorations.