Effect of Dimethyl Sulfoxide wet bonding technique on dentin wettability and resin-dentin bond strength; an In vitro study

Abstract

Objectives: This study evaluated the effect of dimethyl Sulfoxide wet bonding technique in enhancing the dentin bond strength durability and dentin wetting by the adhesive. This pretreatment was compared to ethanol wet bonding technique and the conventional bonding technique. Methods: Extracted human permanent molars were bonded using a two-step etch and rinse adhesive (single bond 2: SB2) after being treated with DMSO (0.004%, 5%, 50%) or ethanol. Dentin specimens (n=10) that received treatments were divided into four groups and specimens that remained untreated served as the control group. Bonded teeth (n=10) were stored in distilled water and then sectioned into resin-dentin sticks for microtensile bond strength testing. Specimens were further divided into 2 subgroups for microtensile testing; one group was evaluated after 24 h while the other after 6 months of aging. The wettability of the adhesive by DMSO vs. ethanol saturated dentin was evaluated through contact angle measurement. Results: The use of 50% DMSO with single bond 2 adhesive showed significantly higher immediate and delayed bond strength than the ethanol and the control groups. DMSO 5% produced similar results as the DMSO 50% in the delayed group. All pretreatments produced significantly lower contact angle compared to the control group. Samples treated with 50% had a significantly lower contact angle value than samples treated with DMSO 0.004%. Significance: Dentin pretreatment using 5% or 50% DMSO may help preserve long term dentinadhesive bond strength as well as improve wetting denoting enhanced adhesive penetration.