Statistical approaches in tensile tests of bond strength

This study aimed to analyze data of bond strength tests of composite resin by different statistical approaches using 48-bovine teeth embedded in acrylic resin after sectioned 2 mm below the cemento-enamel junction and divided into four-groups (n=12). Firstly, micro-tensile test (Mi), Adper Single Bond 2- (3M) was applied over an area of 8 mm2, followed by air jet for 2 to 5s and light cured for 15s and then Z350 XT- (3M) composite resin was inserted. For each tooth a variable number of toothpicks was obtained. For macro-tensile (Ma), the smallest base of the conical specimens was 2 mm. In both tests the specimens were stored differently: G1 Mi and G3 Ma for 24 hours in water, G2 Mi and G4 Ma were artificially aged by thermocycling and then the tests were performed. Data were submitted to exploratory analysis; Weibull analysis; 2-way ANOVA and Tukey; and Student's t-test. Descriptive statistics and Weibull analysis results for the UK (MPa) data were: G1 (modulus; mean ± standard deviation: (2.54; 10.76±4.21); G2 (3.36; 19.34±6.42), G3 (1.96; 3.17±1.51), G4 (1.75; 2.86±1.68). The 2-way ANOVA test, α=5 % indicates significant interaction effect and Tukey (5%). Conclusion: the different statistical strategies indicated the same results.