[ in vitro evaluation of antimicrobial activity of NaCIO and chlorhexidine as intracanal irrigants on streptococcus faecalis]

ABSTRACT

Today most of endodontic treatments are successful and just a low percentage of them may lead to failure. This failure may be due to remaining necrotic and infected agents in root canal system which is because of the complex anatomy of root canal and the rooms not available during mechanical and chemical cleaning. So use of chemical solutions for bacterial disinfection and necrotic agent removal is recommended. The aim of this study was to compare NaCIO Chlorhexidine and normal saline solutions in eradication of S. faecalis as a resistant bacteria in routine endodontic treatments. In this experimental and In vitro study 50 single canal human extracted teeth were selected we made conventional access cavities on all of them. Then, the teeth were divided into five equal groups randomly. Next, they were sterilized in autoclave. After that, we injected S. faecalis in root canals and put them in 37°C incubator for 36 hours. After bacterial growth a culture was prepared from each tooth to determine bacterial growth rate. Finally endodontic treatment was done on the teeth. Duration, method of filling and type of files were the same in groups but the type of chemical solution was different, [group 1 Saline, group 2 Chlorhexidine, group 3 NaCIO 2.5%, group 4 NaCIO 1%, group 5 NaCIO 5.25%]. Another culture was prepared after treatment. At last the number of colony forming units before and after treatment was compared with each other. The data were analyzed by one-way ANOVA. The results showed that there was a significant difference among NaCIO [2.5%, 5.25] and other solutions in decreasing the number of bacteria in root canals after instrumentation. Normal saline, NaCIO 1% and Chlorhexidine solutions developed similar antimicrobial activities. Considering the results of this study, when we have limitations using NaCIO, we Can use Normal Saline as a safe material. In necrotic teeth, use of NaCIO 2.5% for better removal of organisms is recommended