In-vitro Marginal Sealing Ability of Two Self-priming Dentin Bonding Agents

Objectives: The aim of this in vitro study was to compare marginal sealing ability of Class V resin composite restorations using 2 dentin bonding agents, namely Prime & Bond XP and Adper Scotchbond I XT. Methods: Fourty caries free human premolars were selected. In each tooth, one standardized 3mm cylindrical shaped Class V cavity of 1.5mm depth was prepared, with occlusal margins ending in enamel and gingival margins in dentin. The teeth were randomly assigned into 2 groups (n=20). Each adhesive system was applied according to the manufacturer's instructions. The cavities were restored with Esthet X for Prime & Bond XP and with Z250 for Scotchbond XT. After polishing, the specimens were thermocycled (500x, 5-55oC, 30s dwell time) in 0.5% basic methylene blue solution. The specimens were sectioned longitudinally and dye penetration was quantified according to a 0-4 scale on the dentin surfaces and a 0-3 scale on the enamel surfaces independently. Results: Both the dentin bonding agents showed microleakage on the dentinal surfaces; but Prime & Bond XP showed no microleakage in 54% of the sample. On the enamel surfaces Scotchbond XT showed no microleakage in 41% of the sample. A significant difference was found between enamel and dentin for both the dentinal bonding agents (p<0.01). Conclusions: This study shows that both the dentinal bonding agents showed microleakage on the enamel and dentinal surfaces, but Prime & Bond XP might be considered a better clinical choice.