title: Formaldehyde cytotoxicity in three human cell types assessed in three different assays.
abstract: International standards for preclinical screening of the cytotoxicity of dental materials so far recommend the use of established cell lines. The aim of this study was to assess the relative susceptibility of human dental pulp fibroblasts (HPF), human buccal epithelial cells (HBE) and HeLa cervix cancer cells exposed to identical cytotoxic challenges. Formaldehyde, which may be released from dental materials such as dental composites, glassionomer cements, and endodontic sealers, was used as test chemical. Cytotoxicity data including dose-response relations and TC(50) values were assessed in three different assays: BrdU incorporation, neutral red uptake and MTT assays. HBE and HPF demonstrated statistically significant lower TC(50) values in both the neutral red and the BrdU assay in comparison to HeLa cells. In the MTT assay no statistically significant differences were observed between the cell types. In the two target-tissue cell types (HPF and HBE) the Neutral Red assay revealed lower TC(50) values in comparison to the BrdU assay. In HeLa cells no statistically significant differences were observed between the assays. In conclusion, the present study confirms that cytotoxicity data obtained by cell culture studies are influenced by both cell culture model and choice of assay. Under identical experimental conditions, human target tissue cells appeared to be more sensitive to formaldehyde toxicity than human HeLa cancer cells.
authors.affiliation: Tissue Culture Laboratory, Department of Dental Pathology, Royal Dental College, Faculty of Health Sciences, University of Aarhus, DK-8000 Aarhus C, Denmark. loev@odont.au.dk
authors.forename: H
authors.initials: H
authors.lastname: Lovschall
authors.forename: M
authors.initials: M
authors.lastname: Eiskjaer
authors.forename: D
authors.initials: D
authors.lastname: Arenholt-Bindslev
mesh_terms: D001973:Bromodeoxyuridine / Q000378:metabolism; D003782:Dental Pulp / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D005557:Formaldehyde / Q000633:toxicity*; D006367:HeLa Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D009061:Mouth Mucosa / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D009499:Neutral Red / Q000378:metabolism; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013778:Tetrazolium Salts / Q000378:metabolism; D013844:Thiazoles / Q000378:metabolism
chemical_list: D013778:Tetrazolium Salts; D013844:Thiazoles; D005557:Formaldehyde; D009499:Neutral Red; C022616:thiazolyl blue; D001973:Bromodeoxyuridine