An In Vitro Confocal Study to Compare the Effect of Two Cross-Linking Agents on Apical Microleakage of a Root-End Filling Material.

OBJECTIVE(S): This in vitro study was conducted to assess the impact of bioactive glass (BAG) and 6.5% proanthocyanidin (PA) as pretreatment agents on apical microleakage of the root end filling material.

MATERIALS AND

METHODS

Forty-five single-rooted premolars were cleaned, autoclaved, and underwent root canal treatment. The teeth were decoronated to standardize tooth length to 14 mm, with the coronal end sealed with flowable composite. Apical resection at 3 mm from the apex was performed, followed by root end cavity preparation using ultrasonic tips to a depth of 3 mm. Samples were then divided into three groups (n=15): Group A (no pretreatment before mineral trioxide aggregate (MTA) placement), Group B (6.5% PA pretreatment before MTA placement), and Group C (bioactive glass pretreatment before MTA placement). After pretreatment and root end filling in respective groups, samples were coated with nail varnish (except the surface restored with MTA) and immersed in 2% rhodamine B dye for 24 hours, followed by longitudinal sectioning, and examined for apical dye penetration under CLSM (confocal laser scanning microscope) at 40X magnification.

RESULTS

Comparing the mean dye penetration of three groups, ANOVA showed statistically significant dye penetration among the groups (F=117.40, p < 0.001). Further, comparing the difference in mean dye penetration between the groups, Tukey's post-hoc test showed significantly lower dye penetration in both Group B and Group C as compared to Group A. Moreover, the difference in mean dye penetration of Group C showed significantly lower dye penetration as compared to Group B.

CONCLUSION(S): Pretreatment agents significantly improved the sealing ability of root-end filling material by enhancing bonding to dentin through collagen cross-linking, which stabilizes exposed collagen and promotes mineral deposition, thus preventing bacterial infiltration over time.