Investigation into the apical leakage of root-filled teeth prepared for a post crown.

The effect of post canal preparation on the apical seal of endodontically treated teeth was studied in vitro. Single-rooted teeth with mature apices were prepared chemomechanically and obturated with gutta-percha and sealer using one of four techniques: cold lateral condensation, thermo-mechanical compaction, thermomechanical compaction as an adjunct to lateral condensation (hybrid technique), or lateral condensation using an electrically heated spreader, the Endotec. Forty-eight hours after obturation each group of 15 teeth was prepared to accept a post crown. Five teeth in each group were left unprepared as controls. The extent of apical leakage was then determined using a dye, Indian ink, and a clearing technique that rendered the teeth transparent. Linear measurement of the dye penetration was recorded. The results showed that, for each method of obturation, there were no statistically significant differences between the teeth prepared for a post and the unprepared controls. There were no significant differences in leakage between the different groups that had been prepared for a post, or between the control groups.