A COMPARISON OF 2.0-PERCENT CHLORHEXIDINE GLUCONATE AND 5.25-PERCENT SODIUM-HYPOCHLORITE AS ANTIMICROBIAL ENDODONTIC IRRIGANTS

Sodium hypochlorite, as an endodontic irrigant, poses problems includi ng toxicity, odor, and discoloration of operatory items. An equally ef fective, but safer irrigant is desirable. Therefore, we compared the a ntimicrobial activity of 2.0% chlorhexidine gluconate with that of 5.2 5% sodium hypochlorite in an in vitro root canal system. Freshly extra cted human teeth with pulpal pathosis were instrumented using chlorhex idine, sodium hypochlorite, or saline as irrigants. Microbiological sa mples were taken from the teeth immediately after accessing the canal, after instrumentation and irrigation, and after standing in an anaero bic atmosphere for 24 h. Irrigation with chlorhexidine or sodium hypoc hlorite significantly reduced the numbers of postirrigant positive cul tures and colony-forming units compared with saline-irrigated teeth. T he number of postirrigant positive cultures and the number of colony-f orming units in positive cultures obtained from chlorhexidine-treated teeth were lower than the numbers obtained from sodium hypochlorite-tr eated teeth, but the differences were not statistically significant.