Comparison of µTBS of Different Adhesive Systems

Objectives: The purpose of this in-vitro study was to compare the microtensile bond strength (µTBS) of four adhesives to dentin. Methods: Freshly extracted (within 2 weeks) human third molar teeth (n=32) were randomly divided into four groups. One total-etch adhesive (Scotch Bond MP: 3M-Espe) and three self-etching adhesives (Clearfil SE Bond: Kuraray, Clearfil Protect Bond: Kuraray and Prompt L-Pop: 3M-Espe) were applied to mid-coronal dentin surfaces according to the manufacturer's instructions. Resin composites with 4 mm thickness were applied over the adhesives, and the specimens were stored in water for 24 hours at 37⁰C. Then, all specimens were subjected to µTBS testing with a crosshead speed of 1 mm/min after sectioned into 3 to 6 slabs of approximately 1 mm thickness and 2.5 mm width and trimmed interface area of approximately 1 mm². Obtained data from the µTBS testing were statistically analysed by one-way ANOVA / Mann-Whitney post-hoc test. Results: Mean µTBS values in MPa (SD) were: Clearfil SE Bond 34,6^a (5,4), Scotch Bond MP 31,8^a (4,2), Clearfil Protect Bond 30,6^a (3,9) and Prompt L-Pop 24,8^b (5,9). Same superscripts indicate that there is no statistically significant differences. Conclusion: Within the limitations of in-vitro studies, it may be conluded that with the exception of Prompt L-Pop, the µTBS of modern two-step self-etching adhesives are comparable that of evaluated total etch adhesive.