Influence of passive ultrasonic tip activation at different levels on the depth of sealer penetration: An in vitro study

Abstract

Introduction: The aim of this study was to compare the effect between different levels of ultrasonic tip activation on the depth of epoxy resin-based sealer (AH plus) dentinal tubules penetration. Materials and Methods: Extracted single-rooted premolars (n = 60) were randomly allocated into three groups and instrumented following the same protocol. Group 1 (control), the sealer was mixed with 0.1% Rhodamine B dye and placed using size 20 K-file. In Group 2, the sealer was passively activated using ultrasonic tip (ISO 25) 10 s mesiodistally and buccolingually at 2 mm from the apex. In Group 3, the sealer was activated in a similar manner at 4 mm from the apex. Samples were sectioned horizontally at 2 mm, 4 mm, and 6 mm from the apex and analyzed using a stereomicroscope for tubular dentine sealer penetration. The cross-sectional area (μm2) was measured with software to get the percentage of sealer penetration, and presences of voids were recorded. Results: Significant lesser percentage of sealer penetration into the dentinal tubules was observed between the control group and both the experimental groups (P = 0.00) at 2 mm, 4 mm, and 6 mm from the apex. There was no significant difference in the percentage of sealer penetration into the dentinal tubules between both the experimental groups (P > 0.05). The presence of voids between all groups was not statistically significant (P > 0.05). Conclusion: Passive ultrasonic activation of sealer placement resulted in deeper sealer penetration into the dentinal tubules even at a higher level of tip activation (4 mm).