title: Ex vivo biocompatibility tests of regular and white forms of mineral trioxide aggregate.
abstract: OBJECTIVE
  To examine the genotoxicity and cytotoxicity of regular and white mineral trioxide aggregate (MTA) ex vivo by the single-cell gel (comet) assay and trypan blue exclusion test, respectively.
  
  
  METHODS
  Aliquots of 1 x 10(4) Chinese hamster ovary cells were incubated at 37 degrees C for 3 h with grey and white forms of MTA at final concentrations ranging from 1 to 1,000 microg mL(-1). The negative control group was treated with vehicle control phosphate buffer solution for 3 h at 37 degrees C and the positive control group was treated with methyl metasulfonate (at 1 microg mL(-1)) for 1 h at 37 degrees C. After incubation, the cells were centrifuged at 180 g for 5 min and washed twice with fresh medium and resuspended with fresh medium. Each individual treatment was repeated three times consecutively to ensure reproducibility. Parameters from single-cell gel (comet) and cytotoxicity assays were assessed by the Kruskal-Wallis nonparametric test.
  
  
  RESULTS
  Neither compounds produced genotoxic effects with respect to the single-cell gel (comet) assay in all concentrations evaluated. In the same way, the dose-response relationships of all compounds tested at concentrations ranging from 1 to 1,000 microg mL(-1) on cell viability assessed by the trypan blue assay displayed no statistically significant differences (P > 0.05) for either endodontic material.
  
  
  CONCLUSIONS
  Regular (grey) and white MTA are not genotoxins and do not induce cellular death.
authors.affiliation: Department of Pathology, Centre for Genotoxins and Carcinogens Evaluation, TOXICAN, Botucatu Medical School, UNESP, SP, Brazil.
authors.forename: D A
authors.initials: DA
authors.lastname: Ribeiro
authors.forename: M A
authors.initials: MA
authors.lastname: Matsumoto
authors.forename: M A H
authors.initials: MA
authors.lastname: Duarte
authors.forename: M E A
authors.initials: ME
authors.lastname: Marques
authors.forename: D M F
authors.initials: DM
authors.lastname: Salvadori
mesh_terms: D017607:Aluminum Compounds / Q000633:toxicity*; D000818:Animals; D017610:Calcium Compounds / Q000633:toxicity*; D020552:Comet Assay / Q000379:methods; D006224:Cricetinae; D004338:Drug Combinations; D005260:Female; D008422:Materials Testing / Q000379:methods*; D010053:Ovary / Q000166:cytology / Q000187:drug effects; D010087:Oxides / Q000633:toxicity*; D012387:Root Canal Filling Materials / Q000633:toxicity*; D017640:Silicates / Q000633:toxicity*
chemical_list: D017607:Aluminum Compounds; D017610:Calcium Compounds; D004338:Drug Combinations; D010087:Oxides; D012387:Root Canal Filling Materials; D017640:Silicates; C086631:mineral trioxide aggregate