The in vitro antibacterial effect of iodine-potassium iodide and calcium hydroxide in infected dentinal tubules in different time intervals

Aim: The aim of this study was to evaluate the antibacterial effect of iodine-potassium iodide (IKI) and calcium hydroxide (CH) on dentinal tubules infected with Enterococcus faecalis (E. faecalis) at different time intervals. Methods and Materials: Hollow cylinders of bovine root dentin (n=45) were infected and divided into three equal groups filled with either IKI or CH and a positive control. After placing each medicament in the infected cylinders for time periods of 10 minutes, 48 hours and 7 days, microbiological samples were analyzed. At the end of each period, four 100 μm thick inner dentin layers (400 μm thick from each specimen) were removed using dental burs of increasing diameters. Dentin powder was cultured on agar plates to quantitatively assess their infection, expressed in colony forming units (cfu). Results: In all layers of the positive control group, heavy bacterial infection was observed. After 10 minutes, IKI reduced the amount of viable bacteria more efficiently than CH, whereas at later time intervals CH showed the best results. Conclusion: For short periods of exposure, IKI has a more efficient antibacterial effect in the dentinal tubules than CH but CH performs better after longer durations of exposure. Clinical Significance: This research indicates the use of IKI is a better choice for disinfecting the root canal than CH if only a short duration of exposure is used because of its more efficient antibacterial effect. However, if a longer exposure time is used, then CH is a better choice because of its better disinfecting effect over time.