Apical dentin permeability and microleakage associated with root end resection and retrograde filling.

This study evaluated the apical leakage associated with various depths of retrograde fillings placed in root apices which had been resected at one of three different angles. Leakage was assessed with a hydraulic conductance apparatus. Teeth were divided into groups corresponding to the angle of apical resection (0, 30, and 45 degrees to the long axis of the root) and apical leakage was determined following incremental increases in the depth of the retrograde filling (Ketac Silver). Increasing the depth of the retrograde filling significantly decreased apical leakage; there was also a significant increase in leakage as the amount of bevel increased. Both the permeability of resected apical dentin and microleakage around the retrograde filling material had a significant influence on apical leakage.