1. Siqueira JF, Rocas IN. Clinical implications and microbiology of bacterial persistence after treatment procedures. J Endod 2008:34:1291-301.
2. Torabinejad M, Corr R, Handysides R, Shabahang S. Outcomes of nonsurgical retreatment and surgery: a systemic review. J Endod 2009; 35:930- 7.
3. Gu LS, Ling JQ, Wei X, Huang XY. Efficacy of ProTaper Universal rotary retreatment system for gutta-percha removal from root canals. Int Endod J 2008; 41:288–95.
4. Unal GC, Kaya BU, Tac AG, Kececi AD. A comparison of the efficacy of conventional and new retreatment instruments to remove gutta-percha in curved root canals: an ex vivo study. Int Endod J 2009; 42:344–50.
5. Mollo A, Botti G, Prinicipi Goldoni N, Paragliola R, Chazine M, Ounsi HF et al. Efficacy of two NiTi systems and hand files for removing gutta-percha from root canals. Int Endod J 2012; 45:1–6.
6. Gordon MPJ. The removal of gutta-percha and root canal sealers from root canals. N Z Dent J 2005; 101: 44-52.
7. Tasdemir T, Yildirim T, Celik D. Compareative study of removal of current endodontic fillings. J Endod 2008; 34:326-9.
8. Takahashi CM, Cunha RS, de Martin AS, Fontana CE, Silveira CF, da Silveira Bueno CE. In vitro evaluation of the effectiveness of ProTaper universal rotary retreatment system for gutta-percha removal with or without a solvent. J Endod 2009; 35:1580–3.
9. Berutti E, Chiandussi G, Paolino DS, Scotti N, Cantatore G, Castellucci A, et al. Effect of canal length and curvature on working length alteration with WaveOne reciprocating files. J Endod 2011; 37:1687–90.
10. Shen Y, Zhou HM, Zheng YF, Peng B, Haapasalo M. Current challenges and concepts of the thermomechanical treatment of nichkel-titanium instruments. J Endod 2013; 39:163-72.
11. Schirrmeister JF, Wrbas KT, Meyer KM, Altenburger MJ, Hellwig E. Efficacy of different rotary instruments for gutta-percha removal in root canal retreatment. J Endod 2006; 32: 469–72.
12. Ferreira JJ, Rhodes JS, Pitt Ford TR. The efficacy of gutta-percha removal using ProFiles. Int Endod J 2001; 34:267-74.
13. Gergi R, Sabbagh C. Effectiveness of two nickeltitanium rotary instruments and a hand file for removing gutta-percha in severely curved root canals during retreatment: an ex vivo study. Int Endod J 2007; 40: 532-7.
14. Barletta F, Reis M, Wagner M, Borges J, Dall’Agnol C. Computed tomography assessment of three techniques for removal of filling material. Aust Endod J 2008; 34: 101-5.
15. Ma J, Al-Ashwa AJ, Shen Y, Gao Y, Yang Y, Zhang C et al. Efficacy of ProTaper universal rotary retreatment system for gutta-percha removal from oval root canals: a micro-computed tomography study. J Endod 2012; 38:1516-20.
16. Schneider SW. Comparison of the canal preparation in straight and curved root canals. Oral Surg 1971; 32:271-5.
17. Wilcox LR. Endodontic retreatment: ultrasonics and chloroform as the final step in reinstrumentation. J Endod 1989; 15:125–8.
18. Schirrmeister JF, Wrbas KT, Schneider FH, Altenburger M, Hellwig E. Effectiveness of a hand file and three nickel-titanium rotary instruments for removing gutta-percha in curved root canals during retreatment. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2006; 101:542–7.
19. Hulsmann M, Bluhm V. Efficacy, cleaning ability and safety of different rotary NiTi instruments in root canal retreatment. Int Endod J 2004; 37:486- 76.
20. Betti LV, Branante CM, Quantec SC. Rotary instruments versus hand files for gutta-percha removal in root canal retreatment. Int Endod J 2001; 34:514-9.
21. Tasdemir T, Er K, Yildirim T, Celik D. Efficacy of three rotary NiTi instruments in removing guttapercha from root canal. Int Endod J. 2008; 41:191- 6.
22. Hammad M, Qualtrough A, Silikas N. Three dimensional evaluation of effectiveness of hand and rotary instrumentation for retreatment of canals filed with different materials. J Endod 2008; 34: 1370-3.
23. Barletta FB, Rahde Nde M, Limongi O, Moura AA, Zanesco C, Mazocatto G. In vitro comparative analysis of 2 mechanical techniques for removing gutta-percha during retreatment. J Can Dent Assoc 2007; 73:65-65e.
24. Khalilak Z, Vatanpour M, Dadresanfar B, Moshkelgosha P, Nourbakhsh H. In vitro comparison of gutta-percha removal with H-file and ProTaper with or without chloroform. Iran Endod J 2013; 8: 6-9.
25. Teixeria FB, Teixeria EC, Thompson J, Leinfelder KF, Trope M. Dentinal bonding reaches the root canal system. J Esthet Restor Dent 2004; 16:348-54.
26. Cunha RS, De Martin AS, Barros PP, da Silva FM, Jacinto Rde C, Bueno CE. In vitro evaluation of cleansing working time and analysis of the amount of gutta-percha or resilon remnants in the root canal walls after instrumentation for endodontic retreatment. J Endod. 2007; 33:1426-8.
27. Harvath SD, Altenburgerb MJ, Naumann M, Wolkewitz M, Schirrmeister JF. Cleanliness of dentinal tubules following gutta-percha removal with and without solvents: a scaning electron microscopic study. Int Endod J. 2009; 42:1032-8.
28. Zuolo AS, Mello Jr JE, Cunha RS, Zuolo ML, Bueno CES. Efficacy of reciprocating and rotary techniques for removing filling material during root canal retreatment. Int Endod J 2013; 46: 947-53.
29. Rios M, Villela AM, Cunha RS, Velasco RC, De Martin AS, Kato AS, et al. Efficacy of 2 reciprocating systems compared with a rotary retreatment system for gutta -percha removal. J Endod 2014; 40: 1-4.
30. Franco V, Fabiani C, Taschieri S, Malentacca A, Bortolin M, Del Fabbro M. Investigation on the shaping ability of nickeltitanium files when used with a reciprocating motion. J Endod 2011; 37:1398–401.
31. Patel S. New dimensions in endodontic imaging: part 2. Cone beam computed tomography. Int Endod J 2009; 42:463-75.
32. Bramante CM, Fidelis NS, Assumpcao TS, Bernardineli N, Garcia RB, Bramante AS et al. Heat release, time required, and cleaning ability of Mtwo R and protaper universal retreatment system in the removal of filling material. J Endod 2010; 36:1870- 3.
33. Xu LL, Zhang L, Zhou XD, Wang R, Deng YH, Huang DM . Residual filling material in dentinal tubules after gutta-percha removal observed with scanning electron microscopy. J Endod 2012; 38:293-6.
34. Yigit D, Yilmaz A, Sendur G, Aslan O, Abbot P. Efficacy of reciprocating and rotary systems for removing root filling material: A micro-computed tomography study. Scanning 2014; 36:576-581.
35. Silva E, Orlowsky N, Herrera D, Machado R, krebs R, Coutinho-Filho T. Effectiveness of rotatory and reciprocating movements in root canal filling material removal. Braz. Oral res. 2015; 29:1-6.
36. Souza P, Goncalves L, Marques A, Junior E, Garcia L,Carvalho F. Root canal retreatment using reciprocating and continuous rotary nickel-titanium instruments. Eur J Dent 2015; 9:234-39.
37. Hassanloo A, Watson P, Finer Y, Friedman S. Retreatment efficacy of the Epiphany soft resin obturation system. Int Endod J 2007; 40:633-43.
38. Yuruker S, Gorduysus M, Kucukkaya S, Uzunoglu E, Ilgm C, Gulen O et al. Efficacy of combined use of different nickel-titanium files on removing root canal filling material. J Endod 2016; doi.org/10.1016/j.joen.2015.11.019: 1-6.
39. Kim H, Kwak S, Cheung G, Ko D, Lee W. Cyclic fatigue and torsional resistance of two new nickeltitanium instruments used in reciprocating motion: Reciproc versus WaveOne. J Endod 2012; 38:541- 4.
40. Beasley RT, Williamson AE, Justman BC, Qian F. Time required to remove GuttaCore, Thermafil Plus, and Thermoplasticized gutta-percha from moderately curved root canals with ProTaper Files. J Endod 2013; 39:125-8.