title: Cytotoxicity of endodontic materials over 6-weeks ex vivo.
abstract: OBJECTIVE
  To test the hypothesis that extending the time of a traditional ex vivo cytotoxicity test helps to identify trends in the behaviour of root core materials and sealers, which could ultimately aid in predicting their clinical safety and performance.
  
  
  METHODS
  Endodontic sealers and core specimens were initially tested in direct contact with L929 fibroblasts for 72 h. Cell response was estimated by measuring cellular succinate dehydrogenase activity relative to Teflon controls. Cytotoxicity (% of more active cells) was reassessed after 1, 3, 4 and 6 weeks, with the specimens stored in a physiologically balanced salt-solution between tests.
  
  
  RESULTS
  Distinct trends in cytotoxicity among both core materials and sealers were observed over the 6-week test. Four of the six sealers and two of the three core materials showed cell viabilities of <30% of Teflon after 6 weeks (>70% cytotoxicity).
  
  
  CONCLUSIONS
  The current results suggest that some endodontic materials have an elevated biological risk for extended intervals.
authors.affiliation: Department of Oral Rehabilitation, Medical College of Georgia School of Dentistry, Augusta, GA 30912-1260, USA. mbrackett@mail.mcg.edu
authors.forename: M G
authors.initials: MG
authors.lastname: Brackett
authors.forename: A
authors.initials: A
authors.lastname: Marshall
authors.forename: P E
authors.initials: PE
authors.lastname: Lockwood
authors.forename: J B
authors.initials: JB
authors.lastname: Lewis
authors.forename: R L W
authors.initials: RL
authors.lastname: Messer
authors.forename: S
authors.initials: S
authors.lastname: Bouillaguet
authors.forename: J C
authors.initials: JC
authors.lastname: Wataha
mesh_terms: D000818:Animals; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D004396:Coloring Agents; D003188:Composite Resins / Q000633:toxicity; D004129:Dimethylpolysiloxanes / Q000633:toxicity; D004338:Drug Combinations; D004853:Epoxy Resins / Q000633:toxicity; D005347:Fibroblasts / Q000187:drug effects; D005544:Forecasting; D006171:Gutta-Percha / Q000633:toxicity; D008422:Materials Testing; D051379:Mice; D008928:Mitochondria / Q000201:enzymology; D011091:Polyesters / Q000633:toxicity; D019279:Resin Cements / Q000633:toxicity; D012387:Root Canal Filling Materials / Q000633:toxicity*; D012449:Safety; D013385:Succinate Dehydrogenase / Q000187:drug effects; D013778:Tetrazolium Salts; D013844:Thiazoles; D013997:Time Factors; D015035:Zinc Oxide-Eugenol Cement / Q000633:toxicity
chemical_list: D004396:Coloring Agents; D003188:Composite Resins; D004129:Dimethylpolysiloxanes; D004338:Drug Combinations; D004853:Epoxy Resins; C515718:GuttaFlow; D011091:Polyesters; C511498:Real Seal composite resin; D019279:Resin Cements; D012387:Root Canal Filling Materials; D013778:Tetrazolium Salts; D013844:Thiazoles; D015035:Zinc Oxide-Eugenol Cement; C486893:epiphany sealer; C534916:epoxy resin-based root canal sealer; C486892:resilon sealer; C016240:polycaprolactone; D006171:Gutta-Percha; D013385:Succinate Dehydrogenase; C022616:thiazolyl blue