Evaluation of the cytotoxic effects of sodium hypochlorite on human dental stem cells

Shiqi Liu,Pengyu Pan,Hanchao Zhai,Jian Xu,Chengyu Cui,Jinjuan Jiang,Shaoping Fu,Baorong Zhang

doi:10.4314/tjpr.v17i12.9

Abstract

Purpose: To investigate the influence of sodium hypochlorite (NaOCl) on human dental stem cell proliferation and differentiation. Method: Dental pulp stem cells (DPSCs), periodontal ligament stem cell (PDLSCs), and gingival mesenchymal stem cells (GMSCs) were treated with NaOCl. Cell viability was evaluated with cellular counting kit-8 (CCK8), and cellular adenosine triphosphate (ATP) levels were analyzed by bromodeoxyuridine (BrdU) incorporation and subsequent flow cytometry. Quantitative polymerase chain reaction (qPCR) and western blotting were performed to detect the expressions of differentiation markers. Results: The viability and ATP levels of all three stem cells types were impaired by NaOCl in a concentration- and time-dependent manners. However, the decrease ATP in GMSCs was less than the other two stem cell population (p < 0.05). NaOCl treatment significantly suppressed the proliferation of dental stem cells (p < 0.05). With regard to differentiation marker expression levels, the decrease in Stro-1 was greater in treatment groups when compared to control on Day 7, while increase in levels of dentin sialophosphoprotein (DSPP), bone sialoprotein (BSP), and osteocalcin (OC) was smaller (p < 0.05). The expressional changes of Stro-1, DSPP, BSP, and OC were more prominent in DPSMs and PDLSCs than in GMSCs. Conclusion: NaOCl dose-dependently impairs the viability, proliferation and differentiation of dental stem cells. Thus, its toxicity to dental stem cells needs to be considered in clinical application. Keywords: Dental stem cells, Sodium hypochlorite, Viability, Proliferation, Differentiation

Highlights

Sodium hypochlorite (NaOCl), usually used at concentrations from 0.5 to 5.25 %, is one of the most frequently used irrigants in regenerative endodontic procedures because of its bactericidal ability and excellent tissue dissolution capacity [1]
adenosine triphosphate (ATP) levels in DPSCs and Periodontal ligament stem cells (PDLSCs) decreased by nearly 50 % at 0.01 mg/mL of NaOCl at 24 h, when compared to 20 % in gingival mesenchymal stem cells (GMSCs) (p < 0.05)
This suggests that GMSCs are more resistant than DPSCs and PDLSCs to NaOCl-induced ATP loss

Summary

Introduction

Sodium hypochlorite (NaOCl), usually used at concentrations from 0.5 to 5.25 %, is one of the most frequently used irrigants in regenerative endodontic procedures because of its bactericidal ability and excellent tissue dissolution capacity [1]. It is effective and convenient, side effects have been extensively reported in both clinical cases and basic research studies [2]. Previous investigations demonstrated that NaOCl negatively impacts dental stem cell survival and differentiation [3]. -©---2-0--1--8---T--h-e---a--u-t-h--o-r-s--.--T-h--i-s--w--o--r-k--i-s--l-i-c-e--n-s--e--d--u--n--d-e--r--t-h-e---C--r-e--a-t-i-v-e---CT--or-o-m-p-m--J-o-Pn--sh--aA-r-t-mt-r-i-bR-u-e-ts-io-,-nD---4e-c.-0-e-m-In--bt-ee--rr-n-2a--0t-i1o--8n--;a-l-1-L7--i(c-1-e-2n-)-s:--e2--3--7-5 pulp stem cells (DPSCs) was significantly reduced by NaOCl in a dose-dependent manner [4]. 3 % NaOCl reduced the expression of DSPP by 50 %

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