Regaining Apical Patency with Manual and Reciprocating Instrumentation during Retreatment.

Introduction: Different techniques have been proposed to help achieving apical patency during endodontic treatment and retreatment. The objective of this in vitro study was to compare reestablishment of apical patency in teeth previously subjected to root canal treatment using manual and reciprocating instruments.

Methods and Materials: A total of 40 single-rooted extracted human mandibular incisors were selected and prepared using the Hero 642 sequence to 45/0.02 and obturated using Tagger's hybrid technique to 1 mm short of the apex. Teeth were divided into two groups according to the type of instrument used to regain patency: group 1, hand K-files and group 2, reciprocating WaveOne Primary files (25/0.08). Fisher's exact test was used in the statistical analysis. Result: In group1, apical patency was regained in 9 of the 20 teeth tested (46%), compared to 20 teeth (100%) in group 2. The difference between the groups was significant ( P <0.0001).

Conclusion: Our study shows that reciprocating instrumentation is more successful in regaining apical patency in single-rooted, previously treated teeth.