Comparison of endodontic retreatment of laterally condensed gutta-percha and Thermafil with plastic carriers.

The purpose of this study was to evaluate canal wall cleanliness in cases of retreatment using laterally condensed gutta-percha and Thermafil with plastic carriers. Forty extracted mandibular canines were prepared using a step-back flared technique and divided into two groups: group A, obturated with lateral condensation and group B, obturated with Thermafil. AH26 was the sealer used in both groups. Retreatment of all teeth was done using Gates Glidden burs and a solvent. The teeth were then split longitudinally, photographed, and projected onto a screen at x10 magnification. The total area of the canal and the area of gutta-percha/sealer were then traced on white paper. Both areas were accurately quantified using a computerized image analysis system and the ratio of remaining obturation material to root canal periphery was derived and statistically analyzed. Results showed that the average percentage of the remaining gutta-percha/sealer was 14.23 for the lateral condensation group and 15.70 for the Thermafil group with no statistically significant difference (Student's t test, p = 0.01). The plastic carrier was easily removed from the canals.