The influence of cross-sectional shape and surface area on the microtensile bond test

摘要: Abstract Objectives . The purpose of this study was to determine the effect cross-sectional area shape (cylindrical vs rectangular) and bonding surface on microtensile bond strengths stress distribution four dentin adhesive systems (Scotchbond MP Plus, OptiBond FL, Solo, One-Step). In addition, finite element analysis (FEA) models were developed investigate distributions. Methods Extracted human molars cut vertically occlusal enamel removed; one-half tooth used for rectangular specimens, other half cylindrical specimens. bonded according manufacturers' directions covered with a block resin composite. For shaped diamond bur lathe produce specimens 1.1, 1.5 or 3.1 mm 2 at interface. sectioned obtain bar-shaped which hour-glass same as round Bonds stressed in tension speed 1 mm min −1 mean compared using two-way ANOVA, one-way LSD Student's t tests. fractured surfaces examined by scanning electron microscopy, frequencies fracture modes Kruskal–Wallis Mann–Whitney U FEA created simulating areas distribution. Results groups showed significantly lower than 1.1 mm ( p exhibited failure interface between resin. No differences determined mode matched patterns calculated from modeling. Significance results indicate that test methods small higher those larger areas, has little effect. This is probably result fewer defects occurring small-area