Interfacial microleakage between dental adhesives and enamel

Objective:The objective of this study is to evaluate marginal adaptation of three dental adhesives Methods: A flat enamel surface of 3mm in diameter was prepared on the facial surface of 60 extracted cuspid or bicuspid teeth. Dental adhesives (Prime&Bond NT, Xenol III, Adper Prompt) were applied to separately and composite was bonded to the flat surface. A slot was cut thought the center of the flat surface perpendicularly to bonding interface, with a depth excess bonding interface. The teeth bonded by the same adhesive were divided into two groups, one group was subjected to thermocycling (10000X, 5-55C), another water storage. After coated with nail varnish except the slot, all teeth were immersed in a solution of 50% buffered silver nitrate and then a developing solution, followed by section perpendicularly to bonding interface and the slot. The silver penetration along bonding interface was measured under measuring microscope. Results: Prime&Bond NT presented significantly less leakage then Xenol III and Adper Prompt after either water storage or thermocycling (P<0.01). With Prime&Bond NT, the leakage depth of showed no difference between water storage and thermocycling. Xenol III and Adper Promp exhibited no difference in leakage depth. Conclusions: Marginal adaptation in enamel bonded by acid-etching and rinse adhesive is superior to that by self-etching adhesive.2007-->