Influence of dental morphology on microleakage of resin composite restorations

Microleakage test is a simple method and very useful to evaluate the marginal sealing of dental fillings. Objectives: The aim of this research was to evaluate the influence of the dental morphology on the marginal microleakage of class II resin composite restorations with end on dentin, using two types of bonding agent. "Methods: Forty class II restorations were prepared on the mesial and distal surfaces of 20 recently extracted caries-free human molars, with the cervical margins in dentin. To the group I, on the mesial surface was used the adhesive Single Bord (3M ESPE) and on the distal surface was used the adhesive Scotch Bond (3M ESPE). To the group II, on the mesial surface was used Scotch Bond, and on the distal surface was used the adhesive Single Bond. All the cavities were restored with Z250 (3M ESPE) resin. After 24 hours, restorations had received finishing and polishing. The restored teeth were stored in water at 24 hours, thermocycled for 1000 cycles (5 degrees C and 55 degrees C) and then submitted to dye penetration with a 25% silver nitrate solution for 2 hours. After that, samples were sectioned mesiodistally in 3 sections and analyzed with a stereoscopic lens in order to evaluate the leakage on the gingival margin. Data were analyzed using Wilcoxon nonparametric test (5% level of significance). Results: The results demonstrated that p value was 0,237 (ns) to the faces (mesial and distal) and p= 0,454 (ns) to the adhesives.

Conclusions: The authors had concluded that the dental morphology did not interfere on the marginal microleakage of class II resin composite. The adhesives used on this research did not impede the marginal microleakage.