effect of storage media and sterilization method on shear bond strength of composite to enamel of extracted teeth

Aim: to evaluate the effect of storage media and autoclaving on shear bond strength of composite to enamel. materials and methods: 100 human premolars were randomly divided into ten groups of ten as follows: c: freshly extracted teeth. a: autoclaved freshly extracted teeth. ch-6: 6 month storage in 0.5 % chloramine t. ca-6: 6 month storage in 0.5 % chloramine t + autoclaving. t-6: 6 month storage in 0.04 % thymol. ta-6: 6 month storage in 0.4% thymol + autoclaving. ch-12:12 month storage in 0.5 % chloramine t. ca-12: 12 month storage in 0.5 % chloramine t + autoclaving. t-12: 12 month storage in 0.4% thymol. ta-12:12 month storage in 0.4% thymol + autoclaving. one composite cylinder was bonded on each specimen for evaluation of shear bond strength (sbs) and failure modes. data were analyzed using three-way anova, tukey’s post hoc and chi square tests and the level of significance was set at p= 0.05. results: autoclaving and storage media had no significant effect on sbs (p-value = 0.818 for storage media and p-value = 0.221 for autoclaving). however, storage duration significantly changed sbs (p-value = 0.00). there were no correlations among the variables (p-value > 0.05). storage media and duration had no significant effect on failure modes (p-value > 0.05), but autoclaving significantly increased cohesive failure of enamel (p-value =0.039). conclusion: storage of teeth in chloramine t and thymol had no significant effect on bond strength to enamel. although autoclaving of specimens may not alter bond strength, it can significantly increase the cohesive failure of enamel.