In vitro comparison of different reciprocating systems used during endodontic retreatment

The present study evaluated the effectiveness of two reciprocating systems for the removal of root‐filling material during endodontic retreatment. One hundred extracted mandibular premolars were prepared and root‐filled with gutta‐percha and sealer. Root fillings were removed with K‐files according to the following techniques: Group A – hand instrumentation; Group B – Endo‐Gripper system driven by compressed air; Group C – INTRAmatic 29CH + INTRA‐LUX 3LD driven by compressed air; Group D – Endo‐Gripper system driven by electric engine; Group E – INTRAmatic 29CH + INTRA‐LUX 3LD driven by electric engine. The amount of filling debris on root canal walls was assessed radiographically and analysed using Auto CAD 2000 software. One‐way anova and Duncan’s test revealed statistically significant differences only in the middle third (P = 0.01); the best results being reached in group D. The apical third displayed the greatest amount of filling material debris, regardless of the technique used.