Incorporation of dimethyl sulfoxide into experimental hydrophilic and hydrophobic adhesive resins: evaluation of cytotoxic activities

This study evaluated the cytotoxicity of methacrylate‐based resins containing dimethyl sulfoxide (DMSO). DMSO was incorporated into hydrophobic (R2) and hydrophilic (R5) resins at weight concentrations of 0, 0.01, 0.1, 1, 5, or 10 w/w %. Resin discs (n = 10/group) were prepared. Human gingival fibroblasts (HGF‐1) were exposed to resin eluates for 24 h. Furthermore, dentin barrier test was performed using 3‐D cultures of odontoblast‐like cells (SV40 transfected pulp derived cells) with dentin slices of 400 µm thickness (n = 8). After acid etching of dentin, DMSO‐modified resins were applied into the cavity part of the device and light‐cured for 20 s. Cell viability (%) was assessed by MTT and analyzed spectrometrically. Data were analyzed by ANOVA and Tukey test (α = 0.05). Resin eluates showed statistically significantly lower % cell viability for all neat and DMSO‐modified resins than seen for the negative control. Moreover, DMSO‐R5 eluates resulted in significantly lower % cell viability than DMSO‐R2 emulates. The dentin barrier test showed that DMSO‐R2 did not result in significantly lower % cell viability, whereas incorporation of 1‐10 w/w % DMSO into R5 resulted in significantly lower % of cell viability. Incorporating DMSO into hydrophilic self‐etching resins may increase cytotoxicity. The biocompatibility is not influenced by the addition of DMSO into hydrophobic resin.