title: Evaluation of Cytotoxic Effects of Various Endodontic Irrigation Solutions on the Survival of Stem Cell of Human Apical Papilla.
abstract: BACKGROUND
  Root canal disinfection is an important step in regenerative endodontic treatments. An ideal irrigating solution must have high antimicrobial activity and minimum cytotoxicity. This study sought to assess the effect of some irrigating solutions on stem cells from the human apical papilla (SCAP) after different periods of exposure.
  
  
  METHODS
  Stem cells were isolated from immature, impacted mandibular third molars, transferred to 24-well plates, randomly divided into 6 experimental groups and exposed to BioPure MTAD Cleanser, QMix, 17% EDTA, 2% chlorhexidine (CHX), 5.25% sodium hypochlorite (NaOCl), sterile saline and untreated control group. Cytotoxicity of these solutions was assessed after 1, 5 and 15 min of exposure using the methyl thiazol tetrazolium (MTT) assay. Data were statistically analyzed using repeated measures ANOVA. Level of significance was set at 0.05.
  
  
  RESULTS
  The mean percentage of viable cells in all experimental groups was significantly different from the control and sterile saline groups at all the time points (P<0.0001). The mean percentage of viable cells significantly decreased over time in NaOCl, QMix, EDTA and MTAD groups, but no significant reduction was noted in CHX group. At all the time points the highest and the lowest cytotoxicity were seen in MTAD and normal saline groups, respectively. Cytotoxicity of the understudy materials from the highest to the lowest was as follows: MTAD>EDTA>QMax=NaOCl>CHX> sterile saline.
  
  
  CONCLUSIONS
  Chlorhexidine had the lowest cytotoxicity compared to EDTA, MTAD, QMix and NaOCl and its cytotoxicity did not change over time compared to other solutions.
authors: Oral and Dental Diseases Research Center, Department of Endodontics, Dental School, Zahedan University of Medical Sciences, Zahedan, Iran.
authors: Narges
authors: N
authors: Farhad Mollashahi
authors: Oral and Dental Diseases Research Center, Department of Endodontics, Dental School, Zahedan University of Medical Sciences, Zahedan, Iran.
authors: Eshaghali
authors: E
authors: Saberi
authors: Department of Endodontics, Dental School, Hamedan University of Medical Sciences, Hamedan, Iran.
authors: Hamed
authors: H
authors: Karkehabadi
keywords: Apical Papilla; Cytotoxicity; Irrigating Solution; MTT Assay; Stem Cells