Antibacterial efficacy of calcium hydroxide and chlorhexidine gluconate irrigants at 37°C and 46°C

This study investigated the ability of two endodontic irrigants to eliminate Enterococcus faecalis from dentinal tubules, and whether their antimicrobial action was enhanced by heat. The lumens of disks prepared from extracted bovine roots were infected with E. faecalis and incubated for 72 h. Specimens were then filled with saline, 10% calcium hydroxide (Ca(OH)(2)), or 0.12% chlorhexidine gluconate (CHX) at 24degreesC or 46degreesC and incubated at 37degreesC or 46degreesC. The samples were then pulverized and plated to quantify residual bacteria. No statistical difference (p>0.05) in bacterial growth was seen between the two saline groups, or between the two medication groups at a given temperature. CHX and Ca(OH)2 at either temperature produced significantly less growth than either saline group and CHX or Ca(OH)(2) at 46degreesC produced significantly less growth than either group at 37degreesC. Heat enhanced the antibacterial action of both experimental irrigants against E. faecalis, but heating saline produced no increase in bactericidal effect.