title: The effect of sodium hypochlorite and chlorhexidine on cultured human periodontal ligament cells.
abstract: OBJECTIVE
  The objective of this study was to examine the effects of sodium hypochlorite (NaOCl) and chlorhexidine (CHx) on cultured human periodontal ligament (PDL) cells in vitro.
  
  
  METHODS
  The effects of irrigation solutions on human PDL cells were evaluated by propidium iodide fluorescence cytotoxicity assay, protein synthesis assay, and mitochondrial activity.
  
  
  RESULTS
  Both NaOCl and CHx were cytotoxic to human PDL cells in a concentration- and contact time-dependent manner. In addition, CHx inhibited protein synthesis in human PDL cells. Although NaOCl displayed cellular cytotoxicity, it showed no protein inhibition in the PDL cells. Furthermore, both NaOCl and CHx exhibited an inhibitory effect on mitochondrial activity on human PDL cells.
  
  
  CONCLUSIONS
  This study suggests that these irrigation fluids may cause detrimental effects on vital tissues. Its clinical significance, however, needs to be evaluated further because concentration used, exposure time to the agent, and exposure surface area are important factors affecting the resulting effect.
authors.affiliation: School of Dentistry, Chung Shan Medical and Dental College, Taichung, Taiwan.
authors.forename: Y C
authors.initials: YC
authors.lastname: Chang
authors.forename: F M
authors.initials: FM
authors.lastname: Huang
authors.forename: K W
authors.initials: KW
authors.lastname: Tai
authors.forename: M Y
authors.initials: MY
authors.lastname: Chou
mesh_terms: D000891:Anti-Infective Agents, Local / Q000633:toxicity*; D002478:Cells, Cultured; D002710:Chlorhexidine / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D005453:Fluorescence; D006801:Humans; D008928:Mitochondria / Q000187:drug effects; D010513:Periodontal Ligament / Q000166:cytology / Q000187:drug effects*; D011500:Protein Synthesis Inhibitors / Q000633:toxicity; D012388:Root Canal Irrigants / Q000633:toxicity*; D012973:Sodium Hypochlorite / Q000633:toxicity*
chemical_list: D000891:Anti-Infective Agents, Local; D011500:Protein Synthesis Inhibitors; D012388:Root Canal Irrigants; D012973:Sodium Hypochlorite; D002710:Chlorhexidine