Evaluation of shear bond strength of selfª²etching adhesive systems to enamel in different conditions

    MA Zhe, CHEN Jiª²Hua, WANG Hui, WANG Yingª²Jie

    Department of Prosthodontics, College of Stomatology, Fourth Military Medical University, Xi¬ðan 710033£¬China

    ¡¾Abstract¡¿ AIM: To compare immediate and 24 h shear bond strength (SBS) of selfª²etching adhesive systems to enamel in difference conditions. METHODS: Flat enamel surfaces (n=32, thickness 2.0 mm, area 3.5-4.0 mm2) from 20 freshly exreacted intact bovine incisors were produced by wet grinding on a 200, 400, 600ª²grit SiC paper and mounted in acrylic. The adhesive was applied in accordance with the manufacturer¬ðs instructions. 32 specimens were randomized into 4 groups: immediate (selfª²etching and totalª²etching) and 24 h (selfª²etching and totalª²etching). Every group contained 8 specimens. Specimens for immediate bond strength testing were placed in a test machine according to the previously reported method within 1 min of lightª²initiation. Specimens for 24 h bond strength testing were stored in artificial saliva until testing. The crosshead speed was 0.5 mm/min. Total etch systems served as controls. RESULTS: Oneª²way ANOVA revealed that there were significant differences between immediate and 24 h groups(P<0.01); there were also significant differences in comparison with control group(P<0.01). CONCLUSION: The flat enamel surfaces treated in subarid were significantly different from other conditions. The shear of immeª²diate and 24 h is the highest in the condition of the flat enamel surfaces treated in subarid. ......