Comparison of Antibacterial Effect of Calcium Hydroxide Combined With Chlorhexidine and Povidone-Iodine Against Enterococcus faecalis in Dentinal Tubules of Human Incisors: An In Vitro Comparative Study

BACKGROUND AND OBJECTIVES: It has been found that the microorganism behind the failure of root-filled teeth is Enterococcus faecalis, which shows resistance to most of the intra-canal medicaments. Therefore, the purpose of this study was to evaluate the antibacterial efficacy of three intra-canal medications—calcium hydroxide with saline, combinations of calcium hydroxide with 2% chlorhexidine (CHX), and calcium hydroxide with 5% povidone-iodine—against E. faecalis in dentinal tubules of human incisors. MATERIALS AND METHODS: Forty permanent maxillary central incisors were made into standardized segments and infected with E. faecalis. They were treated with a paste made of calcium hydroxide and 2% CHX, calcium hydroxide and 5% povidone-iodine, and calcium hydroxide and saline for 1 week. Dentinal shavings collected from the canal were suspended in thioglycollate broth solution and spread on brain heart infusion agar. Colony-forming units (CFUs) were enumerated and the CFU per milligram of dentin was calculated. The pH of the medicaments used was measured with the help of pH meter. RESULTS: The results showed that the paste made from calcium hydroxide and 2% CHX was significantly more effective than that made from calcium hydroxide and povidone-iodine, and calcium hydroxide and saline. The addition of CHX or povidone-iodine did not affect the alkalinity of calcium hydroxide. CONCLUSION: This study concludes that Ca(OH)(2) + 2% CHX are effective against E. faecalis. Combinations of calcium hydroxide and 5% povidone-iodine showed better antibacterial effect than calcium hydroxide and saline. Ca(OH)(2) + saline was ineffective against E. faecalis.