Comparative Evaluation of Photoactivated Disinfection and an Antioxidant in Modulating the Push-out Bond Strength of AH Plus Sealer: An in vitro Study
Anchal Salecha *
epartment of Conservative Dentistry and Endodontics, SDM College of Dental Sciences and Hospital, Shri Dharmasthala Manjunatheshwara University, Dharwad, Karnataka, India.
Prashant P. Moogi
Department of Conservative Dentistry and Endodontics, SDM College of Dental Sciences and Hospital, Shri Dharmasthala Manjunatheshwara University, Dharwad, Karnataka, India.
Balaram Naik
Department of Conservative Dentistry and Endodontics, SDM College of Dental Sciences and Hospital, Shri Dharmasthala Manjunatheshwara University, Dharwad, Karnataka, India.
Priya Horatti
Department of Conservative Dentistry and Endodontics, SDM College of Dental Sciences and Hospital, Shri Dharmasthala Manjunatheshwara University, Dharwad, Karnataka, India.
Mahantesh Yeli
Department of Conservative Dentistry and Endodontics, SDM College of Dental Sciences and Hospital, Shri Dharmasthala Manjunatheshwara University, Dharwad, Karnataka, India.
Geeta Hiremath
Department of Conservative Dentistry and Endodontics, SDM College of Dental Sciences and Hospital, Shri Dharmasthala Manjunatheshwara University, Dharwad, Karnataka, India.
*Author to whom correspondence should be addressed.
Abstract
Background: Photoactivated disinfection (PAD) using Indocyanine Green (ICG) as a photosensitiser activated by a near-infrared diode laser generates reactive oxygen species (ROS) that provide robust antimicrobial activity within the root canal system. However, residual ROS can inhibit polymerisation of resin-based sealers, thereby compromising the sealer–dentine interfacial bond. Ascorbic acid (AA), a potent biocompatible antioxidant, has the potential to neutralise these free radicals and restore dentine redox balance.
Objective: The present study aimed to evaluate and compare the push-out bond strength of AH Plus sealer following PAD alone and PAD combined with 10% ascorbic acid application.
Materials and Methods: Sixty extracted, single-rooted human maxillary anterior teeth were prepared using ProTaper Gold rotary files and divided into three groups (n = 20 each): Group 1 (Control) – conventional obturation with Gutta-Percha and AH Plus sealer; Group 2 (PAD) – ICG-mediated photoactivated disinfection with an 810-nm diode laser followed by obturation; Group 3 (PAD + AA) – PAD protocol as in Group 2, followed by 10% ascorbic acid irrigation for 10 minutes before obturation. After 7 days of incubation, 1-mm-thick mid-root discs were subjected to push-out bond strength testing using a Universal Testing Machine (UTM). Data were analysed using one-way ANOVA and post hoc Tukey HSD test.
Results: Mean push-out bond strength values were as follows: Group 1 – 0.0119 MPa (SD ± 0.00185); Group 2 – 0.0244 MPa (SD ± 0.00676); Group 3 – 0.0503 MPa (SD ± 0.01272). One-way ANOVA revealed statistically significant differences among groups (F = 74.99; p < 0.0001). Post hoc Tukey HSD confirmed significant pairwise differences between all groups (p < 0.05).
Conclusion: PAD using ICG and a diode laser significantly improves push-out bond strength of AH Plus sealer compared with conventional obturation. The addition of 10% ascorbic acid following PAD significantly further enhances bond strength by neutralising residual ROS and restoring dentine redox balance. This combined protocol may offer a clinically relevant approach to disinfection while supporting sealer–dentine adhesion under the tested in vitro conditions.
Keywords: AH Plus sealer, ascorbic acid, endodontics, indocyanine green, photoactivated disinfection, push-out bond strength