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

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.

Effect of Sonic Agitation of a Binary Mixture of Solvents on Filling Remnants Removal as an Alternative to Apical Enlargement—A Micro-CT Study

“…Previous studies found no differences in the volume of obturation materials removed with the use of traditional endodontic solvents, independently of ultrasonic agitation (PUI) [ 8 , 20 , 21 ]. AH Plus is an epoxy resin-based sealer commonly used due to its adequate properties as an endodontic sealer [ 40 ].…”

“…Concerns about the cytotoxic potential of using solvents and the associated risk of hindering the cleaning process of root canal walls and isthmuses made them fall into disuse [ 8 , 16 , 17 , 18 ]. The efficacy of solvents for retreatment purposes has been assessed in micro-computed tomographic studies (micro-CT), but the results are inconclusive [ 8 , 19 , 20 , 21 ].…”

The use of solvents for gutta‐percha dissolution/removal during endodontic retreatments: A scoping review

“…Of the studies using eucalyptol as the solvent, 22,23,28,39,45,46 only one did not consider its use a disadvantage 23 . However, the study found no significant difference to the other tested methods, such as, mechanical instrumentation with FlexMaster GT Rotary and ProTaper or manual instrumentation with Hedstroem files, without solvent.…”

“…Many studies 1,4‐7,9,10,14‐47 have tested the efficacy of files and solvents in removing residual GP during retreatment, or the amount of material remaining after using different files and solvents. However, which methods are more effective and whether solvents are essential for root material filling removal are still unclear.…”

Comparison of Obturation Removal Efficiency from Straight Root Canals with ProTaper Gold or Reciproc Blue: A Micro-Computed Tomography Study

“…The desobturation phase can be carried out with several approaches, including hand stainless steel instruments, rotary and reciprocating nickel-titanium (NiTi) instruments [6], specific NiTi retreatment files [6], ultrasonic, Gates Glidden burs and auxiliary methods, such as the use of solvents or heat [7].…”