Effect of shortening the etching time on bonding to sound and caries-affected dentin of primary teeth.

PURPOSE: This study aimed to evaluate the influence of shortening the etching time on bonding of an etch-and-rinse and a 2-step self-etch adhesive systems to sound dentin (SD) and caries-affected primary tooth dentin (CAD). METHODS: Flat dentin surfaces from 48 primary molars were assigned to eight groups, according to substrate (SD and CAD- pH-cycling for 14 days), adhesive (Adper Single Bond 2 [SB] and Clearfil SE Bond [CSEB]), and etching time (recommend by manufacturers and reduced by 50 percent). After 24-hour water storage, bonded sticks with cross-sectional area of 0.8 mm 2 were tested for microtensile bond strength (μTBS). Additionally, two teeth per group were prepared to assess interface morphology via scanning electron microscope. The μTBS means were analyzed by ANOVA and Tukey's tests (P<.05). RESULTS: The etching time did not influence the μTBS to SD and CAD. No difference in bonding was observed between adhesives. However, the μTBS values obtained for CAD were lower vs. SD. The etching time interfered in hybrid layer thickness only for SB. Thinner hybrid layers were produced when the primary tooth dentin was acid etched for half the time. CONCLUSION: Shortening the etching time does not jeopardize the bonding to sound and caries-affected dentin of primary teeth.