Removal of Calcium Hydroxide Medicament from the Apical Root Canal using Different Irrigation Methodologies: A Scanning Electron Microscopy Study

Abstract

Introduction: To evaluate the efficiency of different irrigants and agitation techniques in the removal of calcium hydroxide Ca(OH)2 medicament from the root canal walls. Material and Methods: N=84 mandibular premolars were selected for this study. The root canal of these 84 premolars was cleaned up using the ProTaper rotary system up to the file size F3 and then filled with Ca(OH)2 medicament. For seven days, the root samples were maintained at 37o C and 100% relative humidity. The sample was divided into four groups (n=20 each) using random allocation employing different agitation methods: Group 1- MAF - Master Apical File, Group 2 - PUI - Passive Ultrasonic Irrigation, Group 3 - CB - Canal Brush, and Group 4 - FF - F File. Each group was further subdivided into two subgroups based on the specific chelating agent employed: (a) 10% Citric Acid and (b) 17% EDTA. Longitudinal bisection was performed in the apical (lower) third of the root structure. Further, an assessment was done using SEM (scanning electron microscopy) to study the elimination of Ca(OH)2. Kruskal- Wallis and Mann-Whitney tests were used for statistical analysis. Results: Groups 1 (MAF) and Group 3 (CB) showed a significant statistical difference (p<0.05) when compared to Group 2 (PUI) and Group 4 (FF). An insignificant difference (p>0.05) was seen between the performance of chelating agents (10% Citric Acid and 17% EDTA). Conclusion: Irrespective of the specific chelating agents employed, both the PUI (Passive Ultrasonic Irrigation) and FF (F File) agitation techniques exhibited superior efficacy in the removal of Ca(OH)2 medicament from the apical (lower) third when compared to the CB (Canal Brush) and MAF (Master Apical File) methods.