Influence of solvent and a supplementary step with a finishing instrument on filling material removal from canals connected by an isthmus

摘要

Abstract Aim To evaluate the effectiveness of a solvent (eucalyptol) in improving filling material removal from canals connected by isthmuses, and the additional cleaning effect of a finishing instrument. Methodology The mesial canals from 32 mandibular molars (Vertucci's type II morphology) were instrumented and filled with the single‐cone technique using Reciproc R25 gutta‐percha points ( VDW , Munich, Germany) combined with Sealer 26 (Dentsply, Petrópolis, RJ , Brazil). Each root was then subjected to retreatment using the Mtwo instrument system ( VDW ), with or without a solvent ( n ?=?16 per group). The volume of filling material in the canals was assessed by micro‐computed tomographic (micro‐ CT ) scans taken before and after retreatment. Canals with remnants of filling material received a supplementary procedure with the XP ‐endo Finisher R instrument ( FKG Dentaire, La Chaux‐de‐Fonds, Switzerland), with or without eucalyptol, and another micro‐ CT scan was taken. All retreatment procedures were performed inside a cabinet under a controlled temperature (37?°C). Filling material removal was evaluated in the 5‐mm apical canal system for the canal+isthmus space or the isthmus alone. Statistical analyses were performed to compare the removal of filling material with and without eucalyptol, and after a supplementary approach with XP ‐endo Finisher R. The level of significance was set at 5% for all statistical tests ( P ??0.05). Results The amount of filling material removed from the canal+isthmus with Mtwo instruments was 83.2% when no solvent was used and 83.8% using the solvent ( P ??0.05). When the isthmus area was evaluated separately, most specimens were associated with a reduction in the filling material, with no significant difference between the groups with or without using a solvent ( P ??0.05). The supplementary step with XP ‐endo Finisher R significantly improved removal of filling material from both canal and isthmus area ( P ??0.05), regardless of the use of a solvent ( P ??0.05). Conclusion The use of eucalyptol did not improve filling material removal from Vertucci's type II molar mesial canals and isthmuses. XP ‐endo Finisher R significantly enhanced removal of filling material from the canals and isthmuses.