title: The effect of glutathione on 2-hydroxyethylmethacrylate cytotoxicity and on resin-dentine bond strength.
abstract: OBJECTIVE
  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 (μTBS) of etch-and-rinse adhesive.
  
  
  METHODS
  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 Adper Single Bond Plus (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 μTBS testing. Cytotoxicity and μTBS 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).
  
  
  CONCLUSIONS
  Controlled concentrations of GSH had a protective effect against HEMA cytotoxicity. GSH had neither positive nor negative influence on μTBS.
authors.affiliation: Cariology and Operative Dentistry, Department of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan; Global Center of Excellence (GCOE) Program, International Research Center for Molecular Science in Tooth and Bone Diseases at Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Nassar
authors.forename: N
authors.initials: N
authors.lastname: Hiraishi
authors.forename: M S
authors.initials: MS
authors.lastname: Islam
authors.forename: Y
authors.initials: Y
authors.lastname: Tamura
authors.forename: M
authors.initials: M
authors.lastname: Otsuki
authors.forename: S
authors.initials: S
authors.lastname: Kasugai
authors.forename: K
authors.initials: K
authors.lastname: Ohya
authors.forename: J
authors.initials: J
authors.lastname: Tagami
authors.forename: F R
authors.initials: FR
authors.lastname: Tay
mesh_terms: D000818:Animals; D002460:Cell Line; D003782:Dental Pulp / Q000166:cytology*; D003804:Dentin / Q000737:chemistry*; D005978:Glutathione / Q000494:pharmacology*; D006801:Humans; D008689:Methacrylates / Q000737:chemistry*; D051381:Rats; D019279:Resin Cements / Q000737:chemistry*
chemical_list: D008689:Methacrylates; D019279:Resin Cements; C005044:hydroxyethyl methacrylate; D005978:Glutathione
keywords: HEMA cytotoxicity; bond strength; glutathione; pulp cells