Comparative Study of Microleakage in Class II Restorations

Objectives: The aim of this study was to evaluate the occurrence of microleakage in Class II restorations.
Methods: We used 28 extracted molars permanent healthy humans, which were realized cavity and class II restorations in the mesial and distal sides of each tooth, totaling 56 restorations. The teeth were divided into four groups, varying the restorative material: G1 group - Bulk Fill composite resin (3M ESPE); G2 group - Filtek Z350 XT composite resin (3M ESPE); G3 group - TPH composite resin (DENTSPLY); G4 group - Llis composite resin (FGM); always following the guidelines of the manufacturers. In all restorations was used Single Bond Universal (3M ESPE) with selective etching of enamel. After a week, the polishing of restorations was carried out, and the restored surfaces were coated with nail varnish, with a margin of 1 mm below the limits of restoration. The apical foramen of the teeth were sealed with Aradite. For the analysis of microleakage, the teeth were immersed in methylene blue solution 2% for 24 hours, then were sectioned in mesiodistal direction through the center of the restorations, and submitted to analysis of surfaces by SEM and Optical Microscopy. The photomicrographs of each restorer interface allowed the classification and assessment of the level of infiltration. For evaluation the data from this study was employed statistical analysis.
Results: The results revealed worse sealing in G1, with gaps a thickness of approximately 20 micrometers. Regarding the microleakage of restorations, the highest rates were also found in G1 when compared with other groups.
Conclusions: Based on the applied methodology, it can be concluded that none of the groups were able to impede the pigment penetration in the adhesive interface and microleakage was observed in all groups.