A Comparative Evaluation of Removal of Intracanal Calcium Hydroxide with Endoactivator System and Mechanical Instrumentation with K File, Using Two Irrigating Solutions: an in Vitro Study.

Background Calcium Hydroxide [Ca(OH)2] is widely used intracanal medicament in endodontics due to its antimicrobial activity against persistent microorganisms. Although routine use of calcium hydroxide is highly recommended, its removal at the time of canal obturation is equally important and challenging because its remnant might prevent the sealer penetration into dentinal tubules, potentially interact with zinc oxide eugenol sealers making them brittle and granular, and adversely affect the bonding of resin sealer adhesion thus significantly increasing the apical leakage of root canal treated teeth. Removal of intracanal calcium hydroxide is performed usually with different irrigants in combinations with ultrasonic, sonic, hand or rotary instruments. Objective The objective of this study is to evaluate the efficacy of Endoactivator system and mechanical instrumentation with K files using two irrigants for removal of intracanal Ca(OH)2. Method Forty extracted single rooted human mandibular premolars were collected and divided into two groups of 20 samples each (N=40; Group A: 1-20; Group B: 21-40). All samples were decoronated, instrumented, irrigated, dried and filled with Ca(OH)2 paste. Samples were stored in a humidor for a week and were instrumented with conventional k-file (Group A) and Endoactivator system (Group B). A radiograph was taken to evaluate the remnants of intracanal medicament. Result Overall there is not any statistically significant difference on any method of intracanal calcium hydroxide removal (p=0.45). However, on section wise comparison of efficacy of Ca(OH)2 removal, Endoactivator seems to be more effective than hand files on apical section (p=0.047). There is no statistically significant difference on coronal and middle segments between two methods (p=0.99). Conclusion The efficacy of removal of calcium hydroxide medicament from overall canal by conventional method and endoactivator system is similar though endoactivator system seems to be relatively more efficient on apical portion of root.