INTRODUCTION: polymerization shrinkage of composite resins causes stresses that may exceed the strength of the bond with the surrounding tooth structure, leading to interfacial failure. The use of an adhesive system is always required.
OBJECTIVE: The purpose of this in vitro study was to compare the effect of total-etch adhesive system with self-etch adhesive system on microleakage of universal nano-hybrid composite resin when used to restore class V cavities in primary teeth.
MATERIALS AND METHODS: The sample consisted of 50 freshly extracted sound primary teeth. Standardized class V cavity preparations on the buccal surfaces were prepared and the sample was randomly divided into 2 equal groups:
Group I: 25 teeth received total etch adhesive system.
Group II: 25 teeth received self-etch adhesive system.
The cavities were restored with a universal nano-hybrid restorative material. All specimens were thermocycled and immersed in 0.5% basic fuchsine dye at 37C˚ for 24 hours. Basic fuchsine penetration was assessed on a 4 point grading scale (0 to 4) using a stereomicroscope to evaluate the microleakage of the restorations.
RESULTS: Comparing the percentage of microleakage scores of group I and group II at occlusal margin it was found that, the group I was significantly lower than group II (p=0.041). As for percentage of microleakage scores for the gingival margin between groups I and II it was found that there was no significant difference (p=0.741). Comparing the percentage of microleakage scores at both the gingival and occlusal margis of group I and II, no significant difference was revealed (p=0.105) (p=0.278) respectively. The sum of occlusal and gingival percentage of microleakage scores of group I compared to group II revealed no significant difference (p=0.325)..
CONCLUSION: There is no significant difference in microleakage sum scores between total etch and self-etch adhesive system groups. At the occlusal margin, total-etch adhesive system was significantly better than the self-etch adhesive systems.