Microtensile Bond Strength of MDP-Containing Universal Adhesives to Dentin

Abstract

Objectives: The aim of this study is to evaluate the microtensile bond strength (µTBS) of different MDP-containing universal adhesives to dentin. Methods: A total of thirty-six freshly extracted caries-free human permanent molars were divided into six groups according to type of adhesive and etching mode employed which is either etch-and-rinse (ER) or self-etch (SE). The groups were bonded with Adper Single Bond (AD) and Easy One Bond (EO) as controls; Adhese Universal (AU) and Scotchbond Universal (SU) in both etching modes. Bonded specimens were stored in deionized water for 24 hr (n=6). Composite/dentin beams were prepared (1 mm2). µTBS testing were performed. µTBS data were statistically analyzed using two-way ANOVA and multiple comparison post hoc tests. Results: The two-way ANOVA revealed that the µTBS was significantly affected by the “type of adhesive material” (p<0.05) and “method of dentin surface treatment” (p<0.05). Tukey post hoc multiple comparison test showed that there was no significant difference in µTBS between SU ER and both SU SE and AD ER (p>0.05). However, there were significant difference in µTBS between AU ER and both AU SE and AD ER (p<0.05). Comparison among both materials showed that the µTBS of AU ER was significantly higher than SU ER (p>0.05). µTBS of EO SE was significantly lower than all groups (p<0.05). Conclusions: Application of an etching step prior to MDP-containing SU does not affect its µTBS while application of an etching step prior to MDP-containing AU improves its µTBS. Also, MDP-containing AU showed improved µTBS than MDP-containing SU when both used in ER mode.