Epoxy Resin-Based Root Canal Sealer Penetration into Dentin Tubules Does not Improve Root Filling Dislodgement Resistance

This study sought to evaluate the effect of the penetration of an epoxy resin-based root canal sealer into dentin tubules on the force required to dislodge the root canal filling. Sixty extracted human central incisors with single canals were decoronated, instrumented, and filled with gutta-percha and AH Plus sealer labeled with 0.1% rhodamine B dye. The roots were further sectioned horizontally at 3, 6, and 8 mm from the apex. The coronal surfaces of the resulting 180 slices were evaluated using confocal laser scanning microscopy to measure the amount of sealer that penetrated into the dentin tubules. To quantify the force required to dislocate the root filling material, the root fillings of the slices were subjected to a dislodgement resistance test (push-out). Spearman's rho correlation test was further used to test the correlation between the push-out bond strength and sealer penetration into the dentin tubules (P