Confocal laser scanning microscopic investigation of ultrasonic, sonic, and rotary sealer placement techniques

BACKGROUND: Sealers are used to attain an impervious seal between the core material and root canal walls. AIM: To compare the depth and percentage of sealer penetration with three different placement techniques using confocal laser scanning microscopy as the evaluative tool. MATERIALS AND METHODS: Root canals of 30 single-rooted teeth were prepared to a size of F3 and AH plus sealer with Rhodamine B was applied with Ultlrasonic file (Gr-1), lentulospiral (Gr-2), and Endoactivator (Gr-3). Canals were obturated with gutta-percha. The roots were sectioned at the 3 and 6-mm levels from the apical foramen and were examined on a confocal microscope. RESULTS: A statistical significant differences among Gr-1, Gr-2, and Gr-3 were found at the 3 and 6-mm level (P < 0.05; ANOVA-Tukey tests) for the depth and percentage of sealer penetration except for Gr-1 and Gr-2 at 3-mm level. Gr-1 showed maximum mean depth of penetration (810 μm) and maximum mean percentage of sealer penetration (64.5) while Gr-3 showed minimum mean depth of penetration (112.7 μm) and minimum mean percentage of sealer penetration (26.7). CONCLUSION: Depth and percentage of penetration of sealer is influenced by the type of placement technique and by the root canal level with penetration decreasing apically.