Antimicrobial efficacy of chloroxylenol and chlorhexidine in the treatment of infected root canals

Purpose: To investigate the antimicrobial efficacy of a chlorhexidine gluconate (2.0%) and of an ethanolic chloroxylenol solution (10%) as a temporary root canal dressing against selected test microorganisms (Staphylococcus aureus, Streptococcus faecium Escherichia coli, Candida albicans). Materials and Methods: Extracted single-rooted human teeth were instrumented up to size 40. After removal of the smear layer suspensions of the test microorganisms were inserted into the root canals. After incubation for 48 hrs each suspension of the test organisms was removed and the root canals were filled with one of the two different disinfectants. The teeth were then incubated for 48 his. Twelve teeth and three controls were used for each of the four test organisms and each of the two regimens. After incubation, each root canal was instrumented and the removed canal wall dentin was examined microbiologically. Results: With a contact time of 48 hrs between the two disinfectants and the four bacterial suspensions the medications led to a total killing of microorganisms in 82% of a total of 96 contaminated teeth. In the dentin layer situated 50 mum from the root canal, both medications achieved bacterial killing in a range from 99.9% to 99.99%, depending on the test organism, There were no significant differences (P > 0.1) between the relative antimicrobial activity of the two root canal dressings.