Evaluation of Inactivation of Intracanal Antiseptics by Dentin; in Vitro Study

The present study attempts to investigate the tooth dentin influence on antimicrobial efficacy of sodium hypochlorite, chlorhexidine, iodin and potassium iodide. Subjects and Enterococcus foecalis (1394 code) was cultured in TSA environment where the purred colony suspension in concentration of 0.5% peptone water was supplied. In this direction, 15 intact impacted third molars teeth that has been extracted by surgical, chips into dentinal powder through mesh 200 in order to produce suspension of 28 mg dental powder in 50 distilled water, then incubated by irrigate liquid for 1 hr under 37°C. Adding 50 of bacteria suspension results in final suspension applied is culture at 0, 1 and 24 hr. Control group was subjected to 50 of distilled water instead of dental powder. During 24 hours, colonies were counted under the microscope and analyzed by Mann-Whiteny test using SPSS software. Results shows that CHClN 0. 2%, NaOCl 1%, 5%, I 2% and KI 4% eliminate bacteria after 0, 1 and 24 hours while CHX 0.02%, I 0.2%, KI 0.4% were only able to remove bacteria after 24 hr. Reduction of NaOCl concentration from 5% to 1% did not affect its antibacterial efficacy against dentin powder under in vitro during 24 hr period of the experimental conditions. Through this experimental study it is demonstrated that the dentin have the ability to inhibit antibacterial effect of root canal disinfectant material. The amount of inhibition depends on concentration and the time that material are in contact with dentin.