EC Dental Science

Introduction: The key phase in root canal retreatment is removal of the obturation material, which facilitates reinstrumentation, disinfection and refilling of the root canal system. During retreatment, microorganisms, necrotic tissue, filling material or irrigating agents, pushed through the apical foramen may cause postoperative tenderness or periapical lesions. The success of endodontic retreatment may depend on effective removal of filling materials and apically extruded debris. Aim of the Study: To compare the amount of apically extruded debris, time and efficiency of different endodontic instruments during retreatment. Materials and Methods: 45 extracted single canal human teeth were instrumented up to 25.08 and obturated with Ah plus sealer and gutta-percha points using the lateral condensation technique. The samples were randomly divided into three groups (n = 15) depending on the retreatment technique: Hedstrom files; Reciproc; ProTaper. Apically extruded debris was collected in pre-weighed Eppendorf tubes and the assessment was performed using an analytical balance. During retreatment the time needed to obtain the working length was measured. The teeth were then split axially into halves and the residual material from the canal walls was evaluated using a stereomicroscope (x40) and graded from 1 (clean canal walls) to 5 (completely covered walls). Data were statistically analyzed using analysis of variance (ANOVA) and Scheffé post-hoc test. Results: There was no statistically significant difference in the amount of extruded debris between the examined groups. However, the highest amount of apically extruded debris was recorded with the Hedstrom files (0.0046g) and the lowest with the Reciproc system (0.0035g). The shortest time for the removal of filling material from the canals was found for Reciproc Blue system (110 sec.), followed by ProTaper R (125.5 sec.) but without statistically significant difference. Retreatment by hand instruments needed 229.3 sec., which was significantly longer in comparison to groups 2 and 3. The least amount of residual material was found for Reciproc Blue group, followed by ProTaper group (p > 0.05). Hand files group had the most residual filling material on canal walls, which was significantly more in comparison to other two groups (p < 0.05). Conclusion: The research showed that apical extrusion was present in all examined retreatment techniques. The tested rotary systems produced less extruded debris compared to hand files. The fastest and most successful technique was using the Reciproc blue instruments. None of the techniques were able the fully remove the obturation material from the root canal walls.

Keywords:Debris; Extrusion; Retreatment; ProTaper; Reciproc Blue

1. Kaşıkçı Sena., et al. “Effect of different retreatment files using different kinematics on the release of inflammatory mediators in root canal retreatment of single-rooted teeth: a randomized clinical trial”. Clinical Oral Investigations 6 (2023): 3189-3196.
2. Nair P N R. “On the causes of persistent apical periodontitis: a review”. International Endodontic Journal4 (2006): 249-281.
3. Olivieri Juan Gonzalo., et al. “Outcome of nonsurgical root canal retreatment procedures obturated with warm gutta-percha techniques: a longitudinal clinical study”. Journal of Endodontics8 (2023): 963-971.
4. Ng Y-L., et al. “A prospective study of the factors affecting outcomes of non-surgical root canal treatment: part 2: tooth survival”. International Endodontic Journal7 (2011): 610-625.
5. Komabayashi Takashi., et al. “Comprehensive review of current endodontic sealers”. Dental Materials Journal 5 (2020): 703-720.
6. Jurić Kaćunić Danijela., et al. “Efficacy of reciprocating instruments in retreatment of bioactive and resin-based root canal sealers”. Acta Stomatologica Croatica4 (2022): 338-350.
7. Saad Abdulhamied Y., et al. “Efficacy of two rotary NiTi instruments in the removal of Gutta-Percha during root canal retreatment”. Journal of Endodontics1 (2007): 38-41.
8. Huang Xiangya., et al. “Quantitative evaluation of debris extruded apically by using ProTaper Universal Tulsa rotary system in endodontic retreatment”. Journal of Endodontics9 (2007): 1102-1105.
9. Tinaz Ali Cemal., et al. “The effect of disruption of apical constriction on periapical extrusion”. Journal of Endodontics 7 (2005): 533-535.
10. AlOmari Taher., et al. “Incidence of postoperative pain after canal shaping by using Reciproc and Twisted File Adaptive systems: a prospective, randomized clinical trial”. Clinical Oral Investigations7 (2020): 2445-2450.
11. Bıçakcı Hazal., et al. “Influence of rotary instrumentation with continuous irrigation on pain and neuropeptide release levels: a randomized clinical trial”. Journal of Endodontics11 (2016): 1613-1619.
12. Tinoco JM., et al. “Apical extrusion of bacteria when using reciprocating single-file and rotary multifile instrumentation systems”. International Endodontic Journal6 (2014): 560-566.
13. De-Deus Gustavo., et al. “Apically extruded dentin debris by reciprocating single-file and multi-file rotary system”. Clinical Oral Investigations2 (2015): 357-361.
14. Tanalp J and T Güngör. “Apical extrusion of debris: a literature review of an inherent occurrence during root canal treatment”. International Endodontic Journal3 (2014): 211-221.
15. Capar Ismail Davut., et al. “An in vitro comparison of apically extruded debris and instrumentation times with ProTaper Universal, ProTaper Next, Twisted File Adaptive, and HyFlex instruments”. Journal of Endodontics10 (2014): 1638-1641.
16. Koçak M M., et al. “Comparison of ProTaper Next and HyFlex instruments on apical debris extrusion in curved canals”. International Endodontic Journal10 (2016): 996-1000.
17. De-Deus Gustavo André., et al. “Assessment of apically extruded debris produced by the self-adjusting file system”. Journal of Endodontics4 (2014): 526-529.
18. Silva Emmanuel João Nogueira Leal., et al. “Reciprocating versus rotary systems for root filling removal: assessment of the apically extruded material”. Journal of Endodontics12 (2014): 2077-2080.
19. Bernardes RA., et al. “Comparison of three retreatment techniques with ultrasonic activation in flattened canals using micro-computed tomography and scanning electron microscopy”. International Endodontic Journal9 (2016): 890-897.
20. De-Deus Gustavo., et al. “Micro-computed tomographic assessment on the effect of protaper next and twisted file adaptive systems on dentinal cracks”. Journal of Endodontics7 (2015): 1116-1119.
21. Yared G. “Canal preparation using only one Ni-Ti rotary instrument: preliminary observations”. International Endodontic Journal4 (2008): 339-344.
22. Varela-Patiño Purificación., et al. “Alternating versus continuous rotation: a comparative study of the effect on instrument life”. Journal of Endodontics1 (2010): 157-159.
23. AlOmari Taher., et al. “Debris extrusion using reciproc blue and XP endo shaper systems in root canal retreatment”. International Journal of Dentistry (2021): 6697587.
24. Romeiro Kaline., et al. “Reciproc and reciproc blue in the removal of bioceramic and resin-based sealers in retreatment procedures”. Clinical Oral Investigations1 (2020): 405-416.
25. Nayak Gurudutt., et al. “Evaluation of apical extrusion of debris and irrigant using two new reciprocating and one continuous rotation single file systems”. Journal of Dentistry (Tehran, Iran)3 (2014): 302-309.
26. Arslan H., et al. “Comparison of apically extruded debris after root canal instrumentation using Reciproc(^®) instruments with various kinematics”. International Endodontic Journal3 (2016): 307-310.
27. Caviedes-Bucheli J., et al. “The influence of two reciprocating single-file and two rotary-file systems on the apical extrusion of debris and its biological relationship with symptomatic apical periodontitis. A systematic review and meta-analysis”. International Endodontic Journal3 (2016): 255-270.
28. Iriboz Emre and Hesna Sazak Öveçoğlu. “Comparison of ProTaper and Mtwo retreatment systems in the removal of resin-based root canal obturation materials during retreatment”. Australian Endodontic Journal1 (2014): 6-11.
29. Myers G L and S Montgomery. “A comparison of weights of debris extruded apically by conventional filing and Canal Master techniques”. Journal of Endodontics6 (1991): 275-279.
30. Surakanti Jayaprada Reddy., et al. “Comparative evaluation of apically extruded debris during root canal preparation using ProTaper™, Hyflex™ and Waveone™ rotary systems”. Journal of Conservative Dentistry: JCD2 (2014): 129-132.
31. Caviedes-Bucheli Javier., et al. “The effect of three different rotary instrumentation systems on substance P and calcitonin gene-related peptide expression in human periodontal ligament”. Journal of Endodontics12 (2010): 1938-1942.
32. Webber J., et al. “The WaveOne single-file reciprocating system”. Roots International Magazine of Endodontology 7 (2011): 28-33.
33. Reddy S A and M L Hicks. “Apical extrusion of debris using two hand and two rotary instrumentation techniques”. Journal of Endodontics3 (1998): 180-183.
34. Schäfer E and M Vlassis. “Comparative investigation of two rotary nickel-titanium instruments: ProTaper versus RaCe. Part 2. Cleaning effectiveness and shaping ability in severely curved root canals of extracted teeth”. International Endodontic Journal4 (2004): 239-248.
35. Özyürek Taha and Ebru Özsezer Demiryürek. “Efficacy of different nickel-titanium instruments in removing gutta-percha during root canal retreatment”. Journal of Endodontics4 (2016): 646-649.
36. Ersev H., et al. “The efficacy of ProTaper Universal rotary retreatment instrumentation to remove single gutta-percha cones cemented with several endodontic sealers”. International Endodontic Journal8 (2012): 756-762.
37. Caviedes-Bucheli Javier., et al. “Effectiveness, efficiency, and apical extrusion of 2 rotaries and 2 reciprocating systems in removing filling material during endodontic retreatment. A systematic review”. Journal of Clinical and Experimental Dentistry3 (2023): 250-263.
38. Abdelnaby Passent., et al. “In vitro evaluation of filling material removal and apical debris extrusion after retreatment using Reciproc blue, Hyflex EDM and ProTaper retreatment files”. BMC Oral Health1 (2023): 902.
39. Imura N., et al. “A comparison of the relative efficacies of four hand and rotary instrumentation techniques during endodontic retreatment”. International Endodontic Journal4 (2000): 361-366.
40. Rödig T., et al. “Efficacy of reciprocating and rotary NiTi instruments for retreatment of curved root canals assessed by micro-CT”. International Endodontic Journal10 (2014): 942-948.
41. Iriboz Emre., et al. “The efficiency of hand-files, protaper r, reciproc, XP-endo shaper and XP-endo finisher R in the removal of root filling material from oval root canals”. Journal of Dental and Medical Sciences4 (2019): 72-78.
42. De-Deus G., et al. “Effectiveness of Reciproc Blue in removing canal filling material and regaining apical patency”. International Endodontic Journal2 (2019): 250-257.
43. Doğanay Yıldız E and H Arslan. “The effect of blue thermal treatment on endodontic instruments and apical debris extrusion during retreatment procedures”. International Endodontic Journal11 (2019): 1629-1634.
44. Bago I., et al. “Comparison of the effectiveness of various rotary and reciprocating systems with different surface treatments to remove gutta-percha and an epoxy resin-based sealer from straight root canals”. International Endodontic Journal1 (2019): 105-113.
45. Roggendorf M J., et al. “Micro-CT evaluation of residual material in canals filled with Activ GP or GuttaFlow following removal with NiTi instruments”. International Endodontic Journal3 (2010): 200-209.
46. Üstün Y., et al. “The effect of reciprocation versus rotational movement on the incidence of root defects during retreatment procedures”. International Endodontic Journal10 (2015): 952-958.
47. Aksel H., et al. “Micro-CT evaluation of the removal of root fillings using the ProTaper Universal Retreatment system supplemented by the XP-Endo Finisher file”. International Endodontic Journal7 (2019): 1070-1076.
48. Abramovitz I., et al. “The effectiveness of a self-adjusting file to remove residual gutta-percha after retreatment with rotary files”. International Endodontic Journal4 (2012): 386-392.
49. Adel Mamak., et al. “Comparison of the efficacy of NeoNiTi, ProTaper, and reciproc files in the retreatment of curved root canals: a CBCT assessment”. Acta Stomatologica Croatica4 (2022): 351-362.