Antimicrobial substantivity of chlorhexidine-treated bovine root dentin

Previous studies have demonstrated antimicrobial substantivity in root cana l dentin up to 7 days after treatment with chlorhexidine, This in vitro stu dy assessed the antimicrobial substantivity of chlorhexidine-treated bovine root dentin over a period of 21 days. Sixty standardized bovine root secti ons were randomly divided into three equal groups, and their canals immerse d in one of the following solutions: (i) sterile saline; (ii) 2.5% NaOCl; o r (iii) 0.2% chlorhexidine (CHX), Half the specimens in each group were tre ated with the solution for 5 min and the other half for 7 days. After solut ions were removed, the specimens were incubated at 37 degrees C in Brain He art Infusion broth containing Enterococcus faecalis (ATCC 29212), A fresh i noculum was added to the broth every other day over a 21-day period. The ca nals were then enlarged with sterile burs, and the dentin shavings collecte d and cultured for the presence of cultivable bacteria in the dentinal tubu les, Specimens treated with CHX for 7 days demonstrated significantly less dentin colonization by E. faecalis than the other specimens. CHX has potent ial as an intracanal medicament, if it can be applied for a period of at le ast 7 days.