Influence of time and thermocycling on marginal sealing of several dentin adhesive systems

This study evaluated the in vitro microleakage of six dentin adhesive syste ms. Triangle-shaped Class V cavities with coronal margin in enamel and ging ival margin in cementum or root dentin were cut in the buccal surfaces of 9 0 non-carious single-root human teeth. These teeth were randomly assigned i nto six groups (n=15) for the evaluation of six different dentin adhesive s ystems: One Step, Prime & Bond 2.0, Syntac Single, Single Bond, Optibond So lo and Syntac Sprint. The preparations were restored with Degufill Ultra co mposite and polished using the Enhance system. Each group was randomly divi ded into three subgroups (n=5): samples of the first sub-group were immerse d in 2% methylene blue solution for seven days; those of the second subgrou p remained in a similar solution for 31 days; those of the third subgroup w ere thermocycled 500x at 5-55 degreesC and immersed in 2% methylene blue fo r seven days. All 90 teeth were then embedded in methacrylate and bucco-lin gually sectioned; the dye penetration was evaluated using an 0-4 ordinal sc ale. All of the dentin adhesive groups showed minimal leakage at the enamel margins with increased leakage at the gingival margins. Optibond Solo show ed the best outcomes among the dentin adhesives tested.