Removal efficacy of various calcium hydroxide/chlorhexidine medicaments from the root canal with the aid of biological microscope

Aim: An in vitro study was conducted to comparatively evaluate the two techniques – hand instrumentation and ultrasonic file irrigation for removal of various calcium hydroxide (Ca[OH] 2 )/chlorhexidine containing medicaments from the root canal by using Biological microscope and Digital Camera. Materials and Methods: Sixty-four human single-rooted teeth with straight canals were used. Root canal preparation was performed using Pro-taper Universal for Hand use (Dentsply Maillefer, Ballaigues Switzerland). Teeth were randomly divided into three Groups A, B, and C of 21 teeth each, the remaining tooth remained untouched and served as a negative control. Teeth of Group A were filled with Ca(OH) 2 mixed with saline. Teeth of Group B were filled with Ca(OH) 2 mixed with 0.2% chlorhexidine gel. Teeth of Group C were filled with Ca(OH) 2 mixed with 0.12% chlorhexidine solution. Teeth were stored at 37°C and 100% relative humidity for 7 days. Then Ca(OH) 2 was removed using two techniques: hand instrumentation and ultrasonic file irrigation in both groups. Teeth were sectioned longitudinally and observed under Biological microscope and Digital Camera. Results were statistically analyzed with the Mann–Whitney and Kruskal–Wallis test. Results: The results showed a significant difference between hand instrumentation and ultrasonic file irrigation in cervical and middle third, but no statistic difference in apical third. Conclusion: None of the techniques used in this study removed the inter-appointment root canal medicaments completely.