Marginal leakage in direct and indirect composite resin restorations in primary teeth: An in vitro study

Objective The aim of this study was to evaluate the marginal leakage in class II preparations, with margins in enamel, restored with composite resin indirect and direct restorations. Methods Twenty extracted primary molars were chosen and divided at random into two groups: G1 (n = 10) restored by a direct technique and G2 (n = 10) restored by an indirect technique. The composite resin Filtek Z250 (3M) and the Adper Single Bond adhesive (3M) were used in both groups. Teeth were stored in a humid environment at 37 °C for 1 week, thermo cycled (500 cycles, 5 °C and 55 °C), sealed and immersed in a 0.5% basic fuchsine dye for 24 h. Teeth were longitudinally sectioned, in a mesio-distal direction and leakage was assessed. Results No leakage in the specimens from G2 and leakage in four specimens from G1, but the Mann–Whitney test showed that there was no statistically significant difference between the groups, either for occlusal box (p = 0.317) and proximal box (p = 0.067). Conclusion This study demonstrated that direct and indirect class II composite resin restorations with cervical margins in enamel show similar results regarding marginal leakage.