title: In vitro comparison of the cytotoxicity and water sorption of two different denture base systems.
abstract: OBJECTIVE
  Denture base resins have the potential to cause cytotoxicity in vivo, and the mechanical properties of resins are affected by water sorption. There is a correlation between residual monomer and water sorption. Thus, the purpose of this study was to evaluate water sorption and cytotoxicity of light-activated urethane dimethacrylate (UDMA) denture base resin compared to a conventional heat-activated polymethyl methacrylate (PMMA) resin.
  
  
  METHODS
  Two denture base resins, heat-activated PMMA (Meliodent) and light-activated UDMA (Eclipse), were used in this study. Cytotoxicity (5 × 1 mm(2) ) and water sorption (1 × 1 mm(2) ) specimens were made following the manufacturers' instructions (n = 10). Cytotoxicity tests of denture base resins were performed according to ISO10993-5:1999, and water sorption was evaluated according to ISO 1567:1997. ANOVA tests were employed for evaluating data (α = 0.05).
  
  
  RESULTS
  There was no cytotoxic effect in either the PMMA or UDMA group. In addition, contrary to short-term water storage, a significantly lower water sorption value was shown for UDMA resins compared to PMMA resins in both 3- and 6-month storage periods (p = 0.043 and p = 0.002, respectively).
  
  
  CONCLUSIONS
  The tested denture base materials adhered to the ISO standards for both cytotoxicity and water sorption. The cytotoxicity of the light-activated UDMA resin tested was statistically similar to that of the heat-activated PMMA resin; however, the UDMA resin exhibited decreased water sorption in long-term water storage.
authors.affiliation: Associate Professor, Department of Prosthodontics, Faculty of Dentistry, Cumhuriyet University, Sivas, Turkey.
authors.forename: Hakan
authors.initials: H
authors.lastname: Akin
authors.forename: Faik
authors.initials: F
authors.lastname: Tugut
authors.forename: Zubeyde Akin
authors.initials: ZA
authors.lastname: Polat
mesh_terms: D000327:Adsorption; D000818:Animals; D016923:Cell Death / Q000187:drug effects; D002460:Cell Line; D003819:Denture Bases; D005347:Fibroblasts / Q000166:cytology* / Q000187:drug effects; D008689:Methacrylates / Q000494:pharmacology; D051379:Mice; D019904:Polymethyl Methacrylate / Q000494:pharmacology; D011140:Polyurethanes / Q000494:pharmacology; D012117:Resins, Synthetic / Q000494:pharmacology; D014867:Water / Q000737:chemistry*
chemical_list: D008689:Methacrylates; D011140:Polyurethanes; D012117:Resins, Synthetic; D014867:Water; C029824:urethane dimethacrylate luting resin; D019904:Polymethyl Methacrylate
keywords: Eclipse; PMMA; UDMA; cytotoxicity; water sorption