This study was to determine the effect of different angles of apical resection and depths of retrograde filling on apical leakage.
- N=27 extracted single rooted teeth.
- 3 different groups of 9 teeth resected at 0 degrees, 30 degrees and 45 degrees to long axis of tooth. Canals debrided w/ K file and NaOCl, and #4 gates used entire length of canal. Leakage measured initally with no retrograde filling, then increments of retrograde filling (Ketac Silver) were added and retested with each increment of filling for leakage. Leakage was assessed with a hydraulic conductance apparatus.
1. Increased angle of resection led to increased leakage (due to permeability of apical dentin)
- 0 degree resection needed 1mm of retrograde filling for no leakage.
- 30 degree resection needed 2.1mm of filling for no leakage.
- 45 degree resection needed 2.5 mm for no leakage.
2. As the depth of the retrograde filling was progressively increased for each of the specified angles of resection, the apical leakage also decreased.
Increase the depth of the retrograde filling and decrease the amount of bevel as much as possible to decrease apical leakage through dentinal tubules.