Evaluation of chelating effect of chitosan as intracanal lubricant and an irrigant on smear layer removal – An in-vitro scanning electron microscope study

ABSTRACT Aim: The aim of the study is to evaluate the chelating effect of chitosan as intracanal lubricant and an irrigant on smear layer removal. Objective: The objective of the study is to compare the effectiveness of smear layer removal with chitosan gel and ethylenediaminetetraacetic acid (EDTA) gel as an intracanal lubricant and to evaluate the cumulative outcome of chitosan gel and final rinse on smear layer removal compared to EDTA gel and solution. Materials and Methods: Forty single-rooted extracted human premolars were decoronated to a standard length. Cleaning and shaping were carried out using Mtwo rotary instrument and 3% sodium hypochlorite irrigant. Prepared specimens were divided into four equal groups (n = 10). In first two groups, 17% EDTA gel lubricant was used during instrumentation and final rinsing was carried out with 2 ml saline in one group and 2 ml 17% EDTA solution for 1 min in the other. In other two groups, 0.2% chitosan gel was used as lubricant, and final rinsing was carried out with 2 ml saline in one group and 2 ml 0.2% chitosan solution for 3 min in the other group. All the samples were then longitudinally sectioned which were then evaluated under scanning electron microscope for smear layer removal in three levels, i.e., cervical, middle, and apical third. Statistical Analysis Used: Comparison of mean smear layer scores in the coronal middle and apical thirds of the root canals between four study groups was done using Kruskal–Wallis test followed by Mann–Whitney Post hoc analysis for intergroup comparison with P < 0.05 as statistically significant. Results: In coronal, middle, and apical third sections of root canal, EDTA combination and chitosan combination groups demonstrated statistically significant smear layer removal compared to EDTA gel alone and chitosan gel alone groups. Among the gel groups, chitosan gel has shown a significant smear layer removal ability than EDTA gel. Conclusions: 0.2% chitosan gel lubricant and final rinse solution combination showed comparable smear layer removal as that of 17% EDTA gel lubricant and final rinse. While 0.2% chitosan gel lubricant with saline final rinse showed similar smear layer removal ability like 17% EDTA gel with saline final rinse in coronal and middle third, it performed better than EDTA gel in the crucial apical one-third of root canal.