Influence of hydrophobic layer and delayed placement of composite on the marginal adaptation of two self-etch adhesives

AIM: The purpose of this in vitro investigation was to evaluate the influence of hydrophobic layer and delay in placement of composite on marginal adaptation of two self-etch adhesive systems (XENO-III and ALL-BOND SE). MATERIALS AND METHODS: Eighty class V cavities were prepared on intact, extracted human premolars and were divided into 4 groups of 10 teeth each. Group 1: Application of bonding agents as per manufacturer directions and immediate placement of composite; Group 2: Application of bonding agent and composite similar to group1, with hydrophobic layer curing before composite placement; Group 3: Application of bonding agent similar to group 1, with 2 min delay in composite placement; and Group 4: Application similar to group 2 with 2-min delay in composite placement. The specimens were restored and light cured. After thermocycling and immersion in 2% basic Fuchsin dye solution, the teeth were sectioned and dye penetration was observed under a stereomicroscope at 20× magnification. All the samples were scored and results were analyzed using Kruskal-Wallis and Mann-Whitney tests. RESULTS: In group 1, the microleakage along the both enamel and dentin margin was significantly higher than the other groups for both the adhesive systems. There is no significant difference between groups 2, 3 and 4. CONCLUSION: The addition of a more hydrophobic resin layer and delay in composite placement significantly improves the marginal adaptation of self-etch adhesive resin systems.