Comparison of Two Different Methods in the Removal of Oil-Based Calcium Hydroxide From Root Canal System: A Triple-Blinded Randomised Clinical Trial

To compare the effectiveness of rotary master apical file (RMAF) with ultrasonic activation of endodontic file (UAF) in the removal of silicon oil-based calcium hydroxide (SOBCH) from the canal. Methods: Ethical review committee approval and informed consent was obtained. 60 cases with necrotic teeth in which silicon oil-based intracanal medicament (Metapex) was to be placed were randomised in one of the two groups using sealed envelopes containing assignment codes for medicament removal: RMAF and UAF group. After standard protocol of coronal access, cleaning and shaping, silicon oil-based SOBCH was placed using a Lentulo spiral. A periapical radiograph was taken after SOBCH placement to check for adequate adaptation. On 7th day, after instrumentation and medicament removal according to respective group, a second radiograph was taken to evaluate the effectiveness. Effectiveness was calculated using a graded scale in which 0 and 1 are effective and 2 and 3 are ineffective cleaning. Teeth were statistically analyzed using the Mann Whitney U and Chi-square test. Results: There was no statistically significant difference in the removal effectiveness of group RMAF and Group UAF at coronal (P=0.74) middle (P=0.71) and apical third (P=0.68). According to the graded score both techniques were equally effective in cleaning at all thirds of canal (RMAF=Apical: 1.09±0.70, Middle: 0.61±0.80, Coronal: 0.33±0.48 and UAC=Apical: 1.00±0.77, Middle: 0.52±0.74, Coronal: 0.28±0.46). Effectiveness of SOBCH removal using the two methods was not statistically significant between maxillary and mandibular teeth (P=0.35). Conclusion: Both the removal methods, Ultrasonic activation of file and Rotary master apical file, for SOBCH were equally effective in all the thirds of canal. an‎d none of the techniques were able to completely remove the SOBCH. Effectiveness of SOBCH removal using the two methods was not statistically different between maxillary and mandibular teeth.