Search

Aim: To evaluate the bending, buckling and torsional resistance of ProGlider (PG) (Dentsply Sirona, Ballaigues, Switzerland), R-Pilot (RP) (VDW, Munich, Germany) and WaveOne Gold Glider (WOGG) (Dentsply Sirona)., Methodology: Ninety instruments were used: 30 PG (size 0.16, .02v taper), 30 RP (size 0.125, .04 taper) and 30 WOGG (size 0.15, .02v taper). The bending resistance test was performed on 10 randomly selected instruments of each system according to ISO 3630-1 specifications. For the buckling resistance test, a loading was applied in the axial direction of each instrument using a universal test machine, with a 20 N cell and 15 mm min -1 speed, in the axial direction. When a lateral elastic displacement of 1 mm occurred, the force was registered. The torsional resistance test was performed according to ISO 3630-1 specifications. Statistical analysis was performed using one-way anova and post hoc Student-Newman-Keuls test (P < 0.05)., Results: WOGG had the lowest bending resistance, whilst RP had the highest bending resistance (P < 0.05). RP also had the highest buckling resistance, and WOGG had the lowest (P < 0.05). PG had intermediate results regarding bending and buckling resistance, with significant differences to RP and WOGG (P < 0.05). RP had the highest torsional strength and the lowest angular deflection when compared to PG and WOGG (P < 0.05). No differences in the torsional strength and angular deflection were observed between WOGG and PG (P> 0.05)., Conclusion: The glide path instruments had different behaviours in term of bending, buckling and torsional resistance., (© 2020 International Endodontic Journal. Published by John Wiley & Sons Ltd.)

Introduction: This ex vivo study evaluated the intracanal bacterial reduction promoted by chemomechanical preparation using a single-file technique varying the volume, concentration, and retention time of sodium hypochlorite (NaOCl) irrigation in comparison with a multifile system., Methods: Palatal roots from extracted maxillary first molars were selected and anatomically matched based on microcomputed tomographic analysis for group distribution. The canals were contaminated with a fresh mixed bacterial culture grown in anaerobiosis and recently obtained from a tooth with apical periodontitis. Specimens were divided into 4 groups of 24 each according to the following preparation protocols: REC-6LOW (Reciproc R50 instrument [VDW, Munich, Germany], 6% NaOCl, low irrigant volume), REC-2.5LOW (R50, 2.5% NaOCl, low irrigant volume), REC-2.5HI (R50, 2.5% NaOCl, high irrigant volume), and BR-2.5HI (BioRaCe [FKG Dentaire, LaChaux-de-Fonds, Switzerland], 2.5% NaOCl, high irrigant volume). The total time of preparation was recorded. Intracanal bacteriologic samples were taken before and after preparation; DNA was extracted and subjected to quantitative polymerase chain reaction., Results: Bacteria were detected in 22 initial samples from the REC-2.5LOW group and in 23 from the other groups. Intragroup analysis showed that all tested preparation protocols were highly effective in significantly reducing the intracanal bacterial counts (P < .001). Intergroup comparison of bacterial reduction levels revealed a statistically significant difference between BR-2.5HI and REC-2.5LOW (P < .05). Counts of bacteria were 2.5 times significantly higher in REC-2.5LOW compared with BR-2.5HI. No other significant differences were found in quantitative findings (P > .05)., Conclusions: The concerted effects of multiple instruments, the high volume of irrigation, and the long retention time of NaOCl irrigant had a positive influence on intracanal disinfection during chemomechanical preparation., (Copyright © 2019 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

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., (© 2018 International Endodontic Journal. Published by John Wiley & Sons Ltd.)