An In Vitro Comparative Evaluation of the Effect of Two Chelating Agents and Irrigation Techniques on the Push-Out Bond Strength of a Bioceramic-Based Sealer

Abstract

Objective: To compare the push-out bond strength (PBS) and failure modes of root canals obturated with gutta-percha and a bioceramic-based (BC) sealer after final rinsing with either 17% EDTA or 0.2% chitosan, using conventional syringe irrigation and passive ultrasonic irrigation (PUI).

Materials and Methods: Fifty-two extracted human mandibular premolars were selected and sectioned to obtain 16-mm root lengths. The canals were prepared using ProTaper Next rotary files up to size X3 and randomly divided into four groups (n = 13 per group) according to the final irrigant and irrigation method; Group 1: Syringe irrigation with 17% EDTA, Group 2: PUI with 17% EDTA, Group 3: Syringe irrigation with 0.2% Chitosan and Group 4: PUI with 0.2% Chitosan. The root canals were filled with gutta-percha cone size X3 and BC sealer (CeraSeal) using matched single cone technique. After being kept at 37°C and 100% humidity for 2 weeks to allow setting of sealer, the samples were cut at 5 mm from root apex to achieve 2 mm in thickness of dentin disc as the representative of middle 1/3 of root canal. Mechanical dislodgement resistance was examined using a universal testing machine and PBS was calculated. Specimens were examined under stereomicroscope at 40× magnification to define the bond failure mode. One-way analysis of variance (ANOVA), followed by Bonferroni’s post hoc tests, was performed to evaluate the differences in PBS among the groups. Mode of failure was analyzed by Fisher exact test. The level of significance was set at p=0.05.

Results: There were no significant differences in the mean PBS values or failure modes among the experimental groups. Mean PBS values were 1.67±0.76 MPa, 1.88±0.75 MPa, 1.55±0.80 MPa, and 2.29±1.32 MPa for Groups 1–4, respectively. No significant differences were observed among the groups (p=0.202). Likewise, failure mode distributions were not significantly different among the experimental groups (p=0.209).

Conclusion: No significant differences in PBS or failure mode were observed between root canals irrigated with 17% EDTA and those irrigated with 0.2% chitosan.