title: Cytotoxicity of peracetic acid: evaluation of effects on metabolism, structure and cell death.
abstract: OBJECTIVE
  To evaluate the cytotoxicity and the mechanism of cell aggression of peracetic acid (PA) in comparison with sodium hypochlorite (NaOCl).
  
  
  METHODS
  L929 fibroblasts were exposed to 1% PA and 2.5% NaOCl, at several dilutions for 10 min. The following parameters were evaluated: cell metabolism by methylthiazol tetrazolium assay, external morphology by scanning electron microscopy, ultrastructure by transmission electron microscopy, the cytoskeleton by means of actin and α-tubulin labelling, and the type of cell death by flow cytometry (apoptosis/necrosis). The data were analysed by two-way anova and the Bonferroni post-test (α = 0.05).
  
  
  RESULTS
  The PA group had lower cell viability and a higher percentage of necrotic cells than the NaOCl group (P < 0.05). Both solutions diminished cell metabolism, led to destructuring of the cytoskeleton, created changes in the external morphology, resulted in the accumulation of proteins in the rough endoplasmic reticulum and induced cell death predominantly by necrosis. However, these changes were observed in lower doses of PA when compared with NaOCl.
  
  
  CONCLUSIONS
  Although they had the same mechanism of cytotoxicity, 1% PA had greater cytotoxic potential than 2.5% NaOCl.
authors.affiliation: Department of Restorative Dentistry, Araraquara School of Dentistry, UNESP Univ Estadual Paulista, Araraquara, SP, Brazil.
authors.forename: K S
authors.initials: KS
authors.lastname: Viola
authors.affiliation: Department of Restorative Dentistry, Araraquara School of Dentistry, UNESP Univ Estadual Paulista, Araraquara, SP, Brazil.
authors.forename: E M
authors.initials: EM
authors.lastname: Rodrigues
authors.affiliation: Department of Restorative Dentistry, Araraquara School of Dentistry, UNESP Univ Estadual Paulista, Araraquara, SP, Brazil.
authors.forename: M
authors.initials: M
authors.lastname: Tanomaru-Filho
authors.affiliation: Department of Clinical Analysis, Araraquara School of Pharmaceutical Sciences, UNESP Univ Estadual Paulista, Araraquara, SP, Brazil.
authors.forename: I Z
authors.initials: IZ
authors.lastname: Carlos
authors.affiliation: Department of Pathology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil.
authors.forename: S G
authors.initials: SG
authors.lastname: Ramos
authors.affiliation: Department of Restorative Dentistry, Araraquara School of Dentistry, UNESP Univ Estadual Paulista, Araraquara, SP, Brazil.
authors.forename: J M
authors.initials: JM
authors.lastname: Guerreiro-Tanomaru
authors.affiliation: Department of Restorative Dentistry, Araraquara School of Dentistry, UNESP Univ Estadual Paulista, Araraquara, SP, Brazil.
authors.forename: G
authors.identifier: http://orcid.org/0000-0001-7030-3718
authors.initials: G
authors.lastname: Faria
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D018929:Cell Culture Techniques; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D003599:Cytoskeleton / Q000187:drug effects; D004202:Disinfectants / Q000633:toxicity*; D005347:Fibroblasts / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D005434:Flow Cytometry; D051379:Mice; D008854:Microscopy, Electron; D009336:Necrosis; D010463:Peracetic Acid / Q000633:toxicity*; D012973:Sodium Hypochlorite / Q000633:toxicity
chemical_list: D004202:Disinfectants; D012973:Sodium Hypochlorite; D010463:Peracetic Acid
keywords: cytotoxicity; endodontics; fibroblasts; peracetic acid; sodium hypochlorite