title: In vitro cytotoxicity of indirect composite resins: effect of storing in artificial saliva.
abstract: OBJECTIVE
  The aim of this study was to compare the cytotoxic effects of two indirect composite resins (Artglass and Solidex) on the viability of L-929 fibroblast cells at different incubation periods by storing them in artificial saliva (AS).
  
  
  METHODS
  Disk-shaped test samples were prepared according to manufacturers' instructions. Test materials were cured with light source (Dentacolor XS, Heraus Kulzer, Germany). The samples were divided into two groups. The first group's samples were transferred into a culture medium for 1 hour, 24 hours, 72 hours, 1 week and 2 weeks. The other group's samples were transferred into a culture medium for 1 hours, 24 hours, 72 hours, 1 week, and 2 weeks after being stored in AS for 48 hours. The eluates were obtained and pipetted for evaluation onto L-929 mouse fibroblast cultures incubated for 24 hours. Measurements were performed by MTT (3-(4,5)-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay. The degree of cytotoxicity for each sample was determined according to the reference values represented by the cells with a control group.
  
  
  RESULTS
  Statistical significance was determined by ANOVA. Both groups presented lower cell viability in comparison to the control group at all periods. Storing in artificial saliva reduced cytotoxicity significantly (P < 0.05). Stored Artglass and Solidex showed similar effects on cytotoxicity. Nonstored Solidex samples were found more cytotoxic than Artglass samples. The cell survival rate results of 24-hour incubation period were significantly lower than those of the other experimental periods (P < 0.05).
  
  
  CONCLUSIONS
  Storing indirect composite resins in AS may reduce cytotoxic effects on the fibroblast cells. However, resin-based dental materials continue to release sufficient components to cause cytotoxic effects in vitro after 48 hours of storing in AS.
authors.affiliation: Department of Prosthodontics, Faculty of Dentistry, Gazi University, Ankara, Turkey.
authors.forename: Arzu Zeynep
authors.initials: AZ
authors.lastname: Yildirim-Bicer
authors.forename: Gulfem
authors.initials: G
authors.lastname: Ergun
authors.forename: Ferhan
authors.initials: F
authors.lastname: Egilmez
authors.forename: Hisam
authors.initials: H
authors.lastname: Demirkoprulu
mesh_terms: D000818:Animals; D018929:Cell Culture Techniques; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D004396:Coloring Agents; D003188:Composite Resins / Q000633:toxicity*; D017077:Culture Media, Conditioned; D055117:Curing Lights, Dental / Q000145:classification; D003764:Dental Materials / Q000633:toxicity*; D005347:Fibroblasts / Q000187:drug effects; D055115:Light-Curing of Dental Adhesives / Q000295:instrumentation; D008422:Materials Testing; D051379:Mice; D012464:Saliva, Artificial / Q000737:chemistry*; D013778:Tetrazolium Salts; D013844:Thiazoles; D013997:Time Factors
chemical_list: C498018:Artglass (dental composite); D004396:Coloring Agents; D003188:Composite Resins; D017077:Culture Media, Conditioned; D003764:Dental Materials; D012464:Saliva, Artificial; C113676:Solidex; D013778:Tetrazolium Salts; D013844:Thiazoles; C022616:thiazolyl blue