•Purpose: to evaluate one major aspect in the retreatment of root canal failures, i.e. the removal of gutta-percha and sealer from the canal and reinstrumentation of the canal space and to examine the appearance of the root canal walls after gutta-percha and either AH26 or Roth’s 801 sealer were removed by various methods.
•N= 80 extracted single-rooted teeth
•Teeth were C&S using a stepback technique and obturated randomly with GP and Roth’s 801 or AH26 sealers. Followed by placement of cotton and temporization with Cavit, the teeth were radiographed and stored in a at 37~ for 2 weeks.
•Four techniques were used to remove gutta-percha and sealer: method 1–heat and files; method 2–heat, files, and Cavi- Endo; method 3–chloroform and files; and method 4–chloroform, files, and Cavi-Endo.
•teeth were fractured longitudinally. Tracings of the root canal space, sealer, gutta-percha and unknown debris were then made for each sample at a magnification of x12
• Most highlighted Results:
1.All of the teeth examined had some debris remaining in the canals . 2.Sealer accounted for the greatest percentage of debris in canals.
3.Teeth obturated using Roth’s 801 had significantly less debris than those obturated with AH26.
4.When AH26 was the sealer, removal with method 4 resulted in the most remaining debris; there was no significant difference among the other methods.
5.When Roth’s 801 was the sealer, removal with method 1 resulted in the most remaining debris; there was no significant difference among the other methods.
No technique removed all debris. Copious irrigation during the Tx is essential.