Efficacy of calcium hydroxide: chlorhexidine paste as an intracanal medication in bovine dentin.

The purpose of this study was to evaluate the antibacterial efficacy of an intracanal medication composed of calcium hydroxide with 2% chlorhexidine. Dentin from 24 bovine incisors was used. The incisors were made into standardized cylindrical segments of dentin and infected with Enterococcus faecalis. They were then treated with an intracanal paste composed of calcium hydroxide and sterile water or an intracanal paste composed of calcium hydroxide and 2% chlorhexidine for 1 week. Dentin shavings were collected, suspended in solution, and spread on brain-heart infusion agar. After incubation, colony-forming units were enumerated. The amount of bacteria per mg of dentin was determined. The calcium hydroxide paste with 2% chlorhexidine was significantly more effective at killing E. faecalis in the dentinal tubules than calcium hydroxide with water.