[Adhesive performance of infiltrating resin bonded on dentin in vitro].

OBJECTIVE: To evaluate the adhesive interface and micro-tensile bond strength (muTBS) of infiltrating resin directly bonded to normal dentin. METHODS: Twenty extracted human molars were collected and ground to expose fresh dentin surface. An infiltrating resin (ICON, DMG, Germany) was served as experimental group and Clearfil SE Bond adhesive (Kuraray, Japan) as control group. Following the application of primer (Kuraray, Japan), the specimens were applied infiltrating resin or adhesive respectively and blocks of composite resin were built up. The adhesive interfaces were observed using scanning electron microscope (SEM) and the muTBS was measured by micro-tensile test before and after thermal cycling. RESULTS: The infiltrating resin could penetrate into micro-structure of dentin created by SE Bond primer. A layer of about 180 mum-long and dense resin tags was observed under SEM in infiltrating resin group. The muTBSs were (35 +/- 10) MPa before and (35 +/- 9) MPa after thermal cycling respectively in infiltrating resin group, and the difference was not statistically significant (P>0.05). The muTBSs were (38+/-8) MPa before and (24+/-7) MPa after thermal cycling respectively in control group, and the difference was statistically significant (P<0.05). After thermal cycling, the muTBS of infiltrating resin group was significant higher than that of control group. CONCLUSIONS: The infiltrating resin could penetrate into the micro-structure of dentin created by SE Bond primer. The bond strength and the bonding durability of infiltrating resin were similar to that of SE Bond adhesive.