Shear bond strength of two adhesives to bovine dentin contaminated with various astringents.

PURPOSE: To investigate the in vitro shear bond strength of two adhesives to bovine dentin contaminated with various astringents. METHODS: 120 adult bovine incisors were collected and cut to obtain 240 specimens. The specimens were randomly divided into a self-etch adhesive group (N = 120) and a total-etch adhesive group (N = 120). Both of the groups were divided into the following six subgroups: the non-contamination group and the contamination groups 25% Al2(SO4)3 (Orbat sensitive), 25% AlCl3 (Racestyptine), 10% AlCl3 (Roeko Gingiva Liquid), 15.5% Fe2(SO4)3 (Astringedent) and AlCl3 Paste (Astringent Retraction Paste, N = 20 in each subgroup). Each astringent was applied for 1 minute to the dentin surface before rinsing with water spray for 20 seconds. The respective adhesive was then applied according to the manufacturer's instructions. Two composite cylinders were shaped with a mold, cured on the dentin surface of each specimen and sheared off after 1 day and 1 week storage. The shear bond strengths (MPa) were recorded and analyzed with ANOVA. Results: In the self-etching adhesive group, all astringents showed negative effects on dentin bonding (P 0.05).