title: Comparison of the cytotoxic effects and smear layer removing capacity of oxidative potential water, NaOCl and EDTA.
abstract: This study compared the smear layer removing capability and cytotoxicity of NaOCl, EDTA and Oxidative Potential Water (OPW). Fifteen extracted single-rooted human upper incisors were examined in three groups. The root canals were enlarged to the apical foramen with K files to size #60 and irrigated with: (a) NaOCl followed by OPW, (b) OPW during and after instrumentation and (c) NaOCl followed by EDTA and NaOCl. The effect of these irrigants on the smear layer was evaluated using a scanning electron microscope. In vitro cytotoxicity of these irrigants was examined by MTT colorimetric assay. We found that the combination of NaOCl and OPW as well as the application of OPW alone, failed to remove the smear layer from the apical third, whereas the EDTA and NaOCl combination achieved complete removal. OPW, when used during and after instrumentation, removed the smear layer in the middle third more effectively than NaOCl followed by OPW. EDTA exerted more cytotoxic effects at all concentrations tested when compared with OPW and NaOCl.
  
  
  CONCLUSIONS
  (a) OPW was less cytotoxic than other irrigants but did not effectively remove the smear layer, (b) treatment with EDTA followed by NaOCl efficiently removed of the smear layer, but their cytotoxicity should be considered during endodontic therapy.
authors.affiliation: Department of Endodontics, Faculty of Dentistry, Hacettepe University, Ankara, Turkey. aserper@hacettepe.edu.tr
authors.forename: A
authors.initials: A
authors.lastname: Serper
authors.forename: S
authors.initials: S
authors.lastname: Calt
authors.forename: A L
authors.initials: AL
authors.lastname: Dogan
authors.forename: D
authors.initials: D
authors.lastname: Guc
authors.forename: B
authors.initials: B
authors.lastname: Ozçelik
authors.forename: T
authors.initials: T
authors.lastname: Kuraner
mesh_terms: D000818:Animals; D000891:Anti-Infective Agents, Local / Q000494:pharmacology / Q000633:toxicity; D002455:Cell Division / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D002614:Chelating Agents / Q000494:pharmacology / Q000633:toxicity; D003124:Colorimetry; D004396:Coloring Agents; D003786:Dental Pulp Cavity / Q000187:drug effects* / Q000648:ultrastructure; D003804:Dentin / Q000187:drug effects* / Q000648:ultrastructure; D004492:Edetic Acid / Q000494:pharmacology* / Q000633:toxicity; D005347:Fibroblasts / Q000187:drug effects; D006801:Humans; D007180:Incisor; D016014:Linear Models; D051379:Mice; D008855:Microscopy, Electron, Scanning; D012388:Root Canal Irrigants / Q000494:pharmacology* / Q000633:toxicity; D018915:Root Canal Preparation; D016369:Smear Layer; D012973:Sodium Hypochlorite / Q000494:pharmacology* / Q000633:toxicity; D013778:Tetrazolium Salts; D013844:Thiazoles; D014867:Water / Q000494:pharmacology*
chemical_list: D000891:Anti-Infective Agents, Local; D002614:Chelating Agents; D004396:Coloring Agents; D012388:Root Canal Irrigants; D013778:Tetrazolium Salts; D013844:Thiazoles; C106820:oxidative potential water; D014867:Water; D004492:Edetic Acid; D012973:Sodium Hypochlorite; C022616:thiazolyl blue