Comparative Evaluation of Depth of Penetration of AH Plus® Sealer With Different Ratios of Pachymic Acid Using a Confocal Scanning Electron Microscope: An In Vitro Study

Introduction: Modification with pachymic acid (PA) has been seen to reduce the cytotoxicity of freshly mixed AH Plus® sealer (Dentsply Sirona Inc., Charlotte, North Carolina, United States). The efficacy of the sealer is enhanced by its effect of tubular penetration. The aim of this study was to compare the efficacy of AH Plus sealer penetration with the addition of 0.75% PA in the ratios of 10:1 and 5:1 using a confocal scanning electron microscope. Materials and methods: A total of 30 single-rooted mandibular premolar teeth with a single canal were collected and stored in distilled water. All 30 teeth were prepared to a master apical size of 30/0.09 using ProTaper rotary nickel-titanium files (Dentsply Sirona Inc.). The teeth were randomly divided into three groups based on the sealer used for obturation: (i) Group A: AH Plus sealer, (ii) Group B: AH Plus sealer with a 10:1 ratio of 0.75% PA, and (iii) Group C: AH Plus sealer with a 5:1 ratio of 0.75% PA. The obturated teeth were sectioned horizontally at three different levels from the root apex and were studied under a confocal electron microscope. Data were statistically analyzed using ANOVA. Results: Sealer penetration was highest in Group A, measuring 1640.80 ± 4.5 µm, 985.39 ± 3.2 µm, and 387.91 ± 1.9 µm at the coronal, middle, and apical thirds, respectively (p = 0.03). Group B showed penetration depths of 910.04 ± 1.4 µm, 1007.62 ± 1.9 µm, and 635.95 ± 2.8 µm, while Group C demonstrated 823.54 ± 3.7 µm, 334.03 ± 4.6 µm, and 423.92 ± 2.7 µm at the respective root levels. Overall, Group A (unmodified AH Plus) exhibited the greatest sealer penetration. Conclusion: In all regions, AH plus sealer with the addition of 10:1 and 5:1 of 0.75% PA showed lesser penetration than that by the AH Plus sealer alone.