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Abstract:

Objectives: The objective of this project was to determine the fatigue behaviour of three classes of contemporary adhesives bonded to dentin and to compare the results to the micro-tensile bond strength (µTBS) approach. Methods: We measured the micro-tensile fatigue resistance (µTFR) and the µTBS to dentin of a three-step etch&rince adhesive (OptiBond FL, Kerr), a two-step self-etch adhesive (Clearfil SE Bond, Kuraray) and a one-step self-etch adhesive (G-Bond, GC). Preparation and test set-up of the specimens for both µTBS and µTFR were identical. In fatigue, specimens were tested at 2 Hz and at 10 Hz until failure or until 104 cycles were reached. The distribution of the data and the mean load at which 50% of the samples failed (µTFR) was determined (in MPa) using a logistic regression. µTFR of the three adhesives were compared using a multiple logistic regression for each group. Two-way analysis of variance (ANOVA) and Tukey HSD multiple comparisons test were used to determine statistical differences in µTBS. Conclusion: Comparing the three adhesives, the one-step self-etch adhesive recorded significantly lower values in µTBS (p<0.0001) and µTFR at 10 Hz (p=0.0011), while only nearly different at 2 Hz (p=0.0539).