Evaluating the Effects of Various Antioxidants on Dentinal Tubule Penetrability of a Resin-Based Sealer: A Confocal Laser Microscopic Study

Background This study aimed to evaluate the effects of various antioxidants on the dentinal tubule penetrability of a resin-based sealer using confocal laser microscopy. Methodology A total of 60 extracted human teeth were decoronated and prepared using Protaper Gold rotary files. The canals were irrigated sequentially with 3% sodium hypochlorite, 17% ethylenediaminetetraacetic acid, and distilled water. Samples were randomly divided into the following four groups (n = 15) based on the antioxidant used: Group 1 - control (no antioxidant), Group 2 - 6.5% proanthocyanidin, Group 3 - 34% cashew nut shell liquid, and Group 4 - 10% lycopene. Randomization was performed using a computer-generated random sequence to ensure unbiased specimen allocation. Following irrigation and drying, canals were obturated using AH Plus resin sealer mixed with Rhodamine B dye. Transverse sections were then examined under a confocal laser scanning microscope to assess sealer penetration. Data were statistically analyzed using one-way analysis of variance and Kruskal-Wallis tests. Results Group 4 (10% lycopene) demonstrated the greatest dentinal tubule penetration (359.00 ± 1.73 µm), followed by Group 2 (6.5% proanthocyanidin) (287.86 ± 1.55 µm) and Group 3 (34% cashew nut shell liquid) (261.00 ± 1.85 µm). The control group (Group 1) exhibited the least penetration (230.00 ± 1.92 µm). The differences among the groups were statistically significant (p < 0.05). Conclusion This study provides new evidence that antioxidant application enhances resin sealer penetration, potentially improving long-term root canal sealing efficacy. Within the limitations of this in vitro study, 10% lycopene exhibited the highest dentinal tubule penetrability of resin-based sealer, whereas the control group without antioxidant treatment showed the lowest. Antioxidant application may enhance resin sealer penetration and potentially improve the bonding interface.