Author/Authors :
Sedigh-Shams, Mahdi Department of Endodontics - Dental School, Shiraz University of Medical Sciences, Shiraz , Gholami, Ahmad Pharmaceutical Sciences Research Center and Department of Pharmaceutical Biotechnology - Shiraz University of Medical Sciences, Shiraz , Abbaszadegan, Abbas Department of Endodontics - Dental School, Shiraz University of Medical Sciences, Shiraz , Yazdanparast, Roohollah Students' Research Committee - Dental School, Shiraz University of Medical Sciences, Shiraz , Saberi Nejad, Milad Students' Research Committee - Dental School, Shiraz University of Medical Sciences, Shiraz , Safari, Azam Pharmaceutical Sciences Research Center and Department of Pharmaceutical Biotechnology - Shiraz University of Medical Sciences, Shiraz , Nabavizadeh, Mohammadreza Department of Endodontics - Dental School, Shiraz University of Medical Sciences, Shiraz , Ghasemi, Younes Pharmaceutical Sciences Research Center and Department of Pharmaceutical Biotechnology - Shiraz University of Medical Sciences, Shiraz
Abstract :
Introduction: The purpose of this study was to compare the antimicrobial efficacy of sodium
hypochlorite (SH) and calcium hypochlorite (CH) against Enterococcus faecalis (E. faecalis) using
quantitative real-time polymerase chain reaction (qPCR) analysis and also to compare their
cytocompatibility on L929 murine fibroblasts using Mossman’s tetrazolium toxicity (MTT) assay.
Methods and Materials: A broth micro-dilution susceptibility test was used to determine the
minimum inhibitory concentration (MIC) of each irrigant against E. faecalis. Then, the root
canals of 50 mature extracted human mandibular premolars were contaminated with E. faecalis
and were randomly divided into three groups according to the irrigant used (n=20). Canals were
irrigated with SH in group I (n=20) and CH in group II (n=20) at their obtained MIC. In group
III (n=10), sterile saline was used. Microbial sampling was performed before and after
biomechanical preparation. Quantitative PCR was used to quantify E. faecalis in the root canal
samples. For cytocompatibility assessment, L929 murine fibroblasts were exposed to various
concentrations of the irrigants. Results: Irrigation with test materials resulted in significant
reduction in colony forming units (CFU) in post-instrumentation samples (with the MIC values
of SH and CH against E. faecalis being 0.5% and 5%, respectively). However, the reduction in the
normal saline group was not significant (P=0.203). In addition, 5% CH was more effective than
0.5% SH (P=0.006) in eliminating E. faecalis. Among the different concentrations of tested
irrigants, 0.5% CH and 5% SH showed the least and the most cytotoxicity, respectively (P<0.001).
The cytotoxicity of 5% CH and 0.5% SH was similar (P=0.99), and lower than 2.5% SH (P<0.001).
Conclusion: CH at an MIC of 5% was effective in eliminating E. faecalis in planktonic state and
also its biofilm and exhibited comparable cytocompatibility to that of 0.5% SH.
Keywords :
Calcium Hypochlorite , Enterococcus faecalis , Polymerase Chain Reaction , Root Canal Irrigant , Sodium Hypochlorite
