The effect of glutathione on 2‐hydroxyethylmethacrylate cytotoxicity and on resin–dentine bond strength

Aim To evaluate the influence of reduced glutathione ( GSH ) application on 2‐hydroxyethylmethacrylate ( HEMA ) cytotoxicity on rat pulpal cells and evaluate the effect of etched‐dentine treatment with GSH on the immediate microtensile bond strength (μ TBS ) of etch‐and‐rinse adhesive. Methodology The cytotoxicity of 10 mmol L −1 HEMA , 10 mmol L −1 HEMA  + 1 mmol L −1 GSH , 10 mmol L −1 HEMA  + 5 mmol L −1 GSH and 10 mmol L −1 HEMA  + 10 mmol L −1 GSH was compared (6 h and 24 h). Cells viability was measured by means of 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide ( MTT ) assay, followed by morphological observation of cells. Etched‐dentine surfaces were rinsed and treated with one of the following solutions: 2% GSH , 5% GSH or 10% GSH , bonded with A dper S ingle B ond P lus (3M, ESPE, St. Paul, MN, USA) and restored with resin composite. The control group received no GSH treatment. After 1 day of water‐storage at 37 °C, the specimens were subjected to μ TBS testing. Cytotoxicity and μ TBS data were analysed by one‐way anova and Tukey post hoc tests ( P  <   0.05). Results There were significant differences between the groups. HEMA elicited a remarkable toxic effect. 10 mmol L −1 GSH prevented HEMA‐induced damage at both exposure times. Whilst 5 mmol L −1 GSH lost its protective effect at 24‐h exposure time and 1 mmol L −1 GSH showed no protective effect at both exposure times, GSH had no significant effect on the immediate μTBS; however, 5% GSH had higher bond strength value when compared to 10% GSH ( P  =   0.003). Conclusion Controlled concentrations of GSH had a protective effect against HEMA cytotoxicity. GSH had neither positive nor negative influence on μ TBS .