Effect of Dimethyl Sulfoxide as Dentin Surface Pretreatment on Microtensile Bond Strength of Self-Adhesive Versus Conventional Flowable Composite

Abstract

Objective: Evaluation of the microtensile bond strength of self-adhesive flowable composite in comparison with conventional flowable composite/self-etch adhesive system with and without dimethyl sulfoxide surface pretreatment.Methods: Based on the type of composite, 60 recently extracted, intact human permanent molars were randomly divided into two main groups, self-adhesive flowable composite (SAFC) (n = 30) was used in the first group, and conventional flowable composite (CFC) (n = 30) was employed in the second. Afterwards, two subgroups were created for each group according to the surface pretreatment (n = 15). A test of microtensile bond strength (µTBS) was conducted on a sample of 15 specimens. Using a stereomicroscope, the mode of failure was examined. The multiple comparison post hoc test was utilized for statistical analysis of the μTBS data.Results: The multiple comparison test showed that the mictotensile bond strength (μTBS) of self-adhesive flowable composite (SAFC) Fusio Liquid Dentine with dimethyl sulfoxide (DMSO) as surface pretreatment was significantly greater than that of any group (p > 0.05). A comparison test showed that the self-adhesive flowable composite with and without dimethyl sulfoxide (DMSO) surface pretreatment differed significantly upon examination of μTBS (p < 0.05). But when comparing conventional flowable composite with and without dimethyl sulfoxide (DMSO) surface pretreatment, there was no significant difference in μTBS (p > 0.05).Conclusion: The application of dimethyl sulfoxide (DMSO) as a surface pretreatment enhances Fusio Liquid Dentin self-adhesive flowable composite microtensile bond strength to dentin, but it barely affects the Flow-It conventional flowable composite strength.