Methods: Eighty extracted human single-rooted teeth were filled with AH Plus using ultrafil, thermafil, lateral or vertical compaction techniques and divided into two subgroups to retrieve with R-Endo or hand files (n = 10). All techniques were used with the solvent chlorophorm. The folllowing data were recorded: time taken to reach the working length (t1) and; time required for the complete removal of gutta-percha (t2). Additionally, the teeth were split longitudinally and evaluated under stereomicroscope at X4 magnification for residual filling material. Statistical analysis was performed using one-way ANOVA (P < 0.005).
Results: The retreatment procedure that reached the working length (t1) most rapidly was that ultrafil+R-Endo group, followed by ultrafil+hand files, thermafil+hand files, thermafil+R-Endo, lateral compaction+R-Endo, vertical compaction+hand files, vertical comp + R-Endo, lateral compaction+hand files. Time for complete removal of gutta-percha (t2) was again the shortest with ultrafil+R-Endo, followed by thermafil+R-Endo, vertical compaction+R-Endo, ultrafil+hand files, vertical compaction+hand files, lateral compaction+R-Endo, lateral compaction+hand files, thermafil+hand files. No significant differences were found between the groups in t2 time. There were visible filling material extruded apically in all groups but it was much more in R-Endo groups than the hand files groups. Evaluation of total time of retreatment is demonstrated that there were significant difference between R-Endo and hand files with regard to filling techniques.
Conclusions: Ultrafil retreatment was the the shortest in which made with both R-Endo and hand files, whereas lateral compaction+hand files was the slowest one. When the efficacy and treatment times was compared, a significant difference was found among R-Endo and hand files groups.
Keywords: chlorophorm, R-Endo, gutta-percha removal, root canal retreatment