Effect of Vehicle and Agitation Methods on the Penetration of Calcium Hydroxide Paste in the Dentinal Tubules

Introduction: The aim of this ex vivo study was to analyze the effect of different vehicles combined with agitation methods on the penetration of calcium hydroxide (CH) paste in the dentinal tubules. Methods: Sixty freshly extracted, single-rooted human premolars were prepared using WaveOne Gold (Dentsply Sirona, York, PA) and randomized into 6 experimental groups (n = 10) according to the vehicle and method of paste agitation as follows: propylene glycol (PG) + Lentulo, PG + Lentulo + ultrasound, PG + Lentulo + sonic, distilled water (DV + Lentulo, DW + Lentulo + ultrasonic, and DW + Lentulo + sonic. The CH paste was manipulated with sodium fluorescein dye and was inserted to completely fill the root canal. Two 1-mm thick sections at 2 mm and 5 mm from the apex of each root were obtained. The sections were scanned using confocal laser scanning microscopy, and the images were analyzed using ImageJ software (Bethesda, MD) to calculate the percentage penetration and maximum penetration depth of CH paste. Statistical analysis was performed using 1-way analysis of variance and Tukey honestly significant difference post hoc tests. Results: No statistically significant differences between study factors at a distance of 2 mm from the apex were observed (P > .05). However, at 5 mm, a significant difference between the vehicles (P < .05) in percentage penetration was demonstrated with higher means for PG. Conclusions: Vehicles interfered with the penetration of CH in the dentinal tubules at 5 mm from the apex with better results for PG.