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.