Concentration-dependent effect of sodium hypochlorite on stem cells of apical papilla survival and differentiation

J Endod. 2014 Jan;40(1):51-5. doi: 10.1016/j.joen.2013.07.026. Epub 2013 Oct 25.


Introduction: Intracanal disinfection is a crucial step in regenerative endodontic procedures. Most published cases suggest the use of sodium hypochlorite (NaOCl) as the primary irrigant. However, the effect of clinically used concentrations of NaOCl on the survival and differentiation of stem cells is largely unknown. In this study, we tested the effect of various concentrations of NaOCl on the stem cells of the apical papilla (SCAPs) survival and dentin sialophosphoprotein (DSPP) expression.

Methods: Standardized root canals were created in extracted human teeth and irrigated with NaOCl (0.5%, 1.5%, 3%, or 6%) followed by 17% EDTA or sterile saline. SCAPs in a hyaluronic acid-based scaffold were seeded into the canals and cultured for 7 days. Next, viable cells were quantified using a luminescence assay, and DSPP expression was evaluated using quantitative real-time polymerase chain reaction.

Results: There was a significant reduction in survival and DSPP expression in the group treated with 6% NaOCl compared with the untreated control group. Comparable survival was observed in the groups treated with the lower concentrations of NaOCl, but greater DSPP expression was observed in the 1.5% NaOCl group. In addition, 17% EDTA resulted in increased survival and DSPP expression partially reversing the deleterious effects of NaOCl.

Conclusions: Collectively, the results suggest that dentin conditioning with high concentrations of NaOCl has a profound negative effect on the survival and differentiation of SCAPs. However, this effect can be prevented with the use of 1.5% NaOCl followed by 17% EDTA. The inclusion of this irrigation regimen might be beneficial in regenerative endodontic procedures.

Keywords: Dentin conditioning; EDTA; dentin sialophosphoprotein; gene expression; irrigant; regenerative endodontics; sodium hypochlorite; stem cells of apical papilla; survival; viability.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Culture Techniques
  • Cell Differentiation / drug effects
  • Cell Survival / drug effects
  • Cells, Cultured
  • Dental Papilla / cytology
  • Dentin / cytology
  • Dose-Response Relationship, Drug
  • Edetic Acid / therapeutic use
  • Extracellular Matrix Proteins / analysis
  • Extracellular Matrix Proteins / drug effects
  • Humans
  • Hyaluronic Acid / chemistry
  • Luminescent Agents
  • Odontoblasts / drug effects
  • Phosphoproteins / analysis
  • Phosphoproteins / drug effects
  • Root Canal Irrigants / administration & dosage
  • Root Canal Irrigants / pharmacology*
  • Sialoglycoproteins / analysis
  • Sialoglycoproteins / drug effects
  • Sodium Hypochlorite / administration & dosage
  • Sodium Hypochlorite / pharmacology*
  • Stem Cells / drug effects*
  • Tissue Engineering / methods
  • Tissue Scaffolds / chemistry
  • Tooth Apex / cytology


  • Extracellular Matrix Proteins
  • Luminescent Agents
  • Phosphoproteins
  • Root Canal Irrigants
  • Sialoglycoproteins
  • dentin sialophosphoprotein
  • Hyaluronic Acid
  • Edetic Acid
  • Sodium Hypochlorite