No abstract

The objective was to evaluate effect of dimethyl sulfoxide (DMSO) on microtensile bond strength (µTBS) and nanoleakage (NL). Superficial dentin was acid-etched and pretreated with DMSO. Etch-and-rinse adhesive was applied and restored with resin composite incrementally. After 24 h, teeth were sectioned, stored in artificial saliva for 24-h or 6-months before µTBS evaluation. Failure modes were examined. Six beams per group were submitted to nanoleakage evaluation using SEM. Data were analyzed using ANOVA and Tukey's test (α=0.05). Pretreatment had no significant effect on µTBS after 24 h (p>0.05). After 6 months storage, µTBS of control decreased significantly, more than with the groups treated with 0.01% or higher (p<0.05). DMSO-pretreated groups preserved µTBS in all groups. After 6-months, all groups except 0.001% showed significantly lower nanoleakege compared to control (p<0.05). DMSO (0.01-20%) may improve the hybrid layer integrity and bonding durability. The best results were seen with low (1-5%) of DMSO concentrations.

No abstract

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.