Incidence of dentinal crack formation during root canal preparation with two NiTi instruments activated by adaptive motion and continuous rotation: an in vitro study

Abstract

Objectives: The aim of this study was to evaluate dentin crack incidence after root canal instrumentation using ProTaper Next (PT Next; Dentsply Maillefer, Ballaigues, Switzerland) and Twisted File Adaptive (TF Adaptive; Sybron Endo, Orange, California, USA) at different kinematics.

Methods: Sixty human extracted premolar teeth were selected and divided into 4 main groups. Group 1: PT Next with continuous rotation (n = 15); Group 2: PT Next with adaptive motion (n = 15); Group 3: TF Adaptive with continuous rotation (n = 15); Group 4: TF Adaptive with adaptive motion (n = 15). Fifteen unprepared teeth were used as control group. Crowns of the teeth were removed and roots were sectioned at 3, 6, and 9 mm from the apex using a diamond saw. Finally root dentin pieces were evaluated under stereomicroscope at x25 magnification. Digital images were evaluated by 2 researchers.

Results: No cracks were observed in the control group. In groups 2 and 4 no fracture was observed at the level of 9 mm and similarly in group 4 at 6 mm level. Group 3 showed a significantly higher dentin crack formation followed by Group 1, 2, 4 and control group respectively (p < 0.039). There was no significant difference between groups at 6 mm and 9 mm levels (p = 0.497) except for only 3 mm level (p < 0.035).

Conclusions: It was concluded, both adaptive motion and continuous rotationpromoted dentinal defect. Adaptive motion produced less dentinal defects all dentin levels but there was no significant difference.

Keywords

• Dentinal crack,root canal preparation,protaper next,twisted file adaptive,nickel-titanium instruments,adaptive motion,continuous rotation

References

1. [1] Young GR, Parashos P, Messer HH. The principals of techniques for cleaning root canals. Aust Dent J 2007;52(1 Suppl):S52-63.
2. [2] Wildey WL, Senia ES, Montgomery S. Another look at root canal instrumentation. Oral Surg Oral Med Oral Pathol 1992;74:499-507.
3. [3] Hulsmann M, Peters OA, Dummer PM. Mechanical preparation of root canals: shaping goals, techniques and means. Endod Topics 2005;10:30-76.
4. [4] Peters OA. Current challenges and concepts in the preparation of root canal systems: a review. J Endod 2004;30:559-67.
5. [5] Zandbiglari T, Davids H, Schafer E. Influence of instrument taper on the resistance to fracture of endodontically treated roots. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2006;101:126-31.
6. [6] Bier CA, Shemesh H, Tanomaru Filho M, Wesselink PR, Wu MK. The ability of different nickel-titanium rotary instruments to induce dentinal damage during canal preparation. J Endod 2009;35:236-8.
7. [7] Adorno CG, Yoshioka T, Suda H. The effect of root preparation technique and instrumentation length on the development of apical root cracks. J Endod 2009;35:389-92.
8. [8] Burklein S, Tsotsis P, Schafer E. Incidence of dentinal defects after root canal preparation: reciprocating versus rotary instrumentation. J Endod 2013;39:501-4.

9. [9] Ruddle CJ. Single-file shaping technique: achieving a gold medal result. Dent Today 2012;1:1-7.
10. [10] Liu R, Hou BX, Wesselink PR, Wu MK, Shemesh H. The incidence of root microcracks caused by 3 different single-file systems versus the ProTaper system. J Endod 2013;39:1054-6.
11. [11] Karataş E, Gündüz HA, Kırıcı DÖ, Arslan H, Topçu MÇ, Yeter KY. Dentinal crack formation during root canal preparations by the twisted file adaptive, ProTaper Next, ProTaper Universal, and WaveOne instruments. J Endod 2015;41:261-4.
12. [12] Shemesh H, van Soest G, Wu MK, Wesselink PR. Diagnosis of vertical root fractures with optical coherence tomography. J Endod 2008;34:739-42.
13. [13] Kansal R, Rajput A, Talwar S, Roongta R, Verma M. Assessment of dentinal damage during canal preparation using reciprocating and rotary files. J Endod. 2014;40:1443-6.
14. [14] Arias A, Lee YH, Peters CI, Gluskin AH, Peters OA. Comparison of 2 canal preparation techniques in the induction of microcracks: a pilot study with cadaver mandibles. J Endod 2014;40:982-5.
15. [15] Varela-Patiño P, Ibañez-Párraga A, Rivas-Mundiña B, Cantatore G, Otero XL, Martin-Biedma B. Alternating versus continuous rotation: a comparative study of the effect on instrument life. J Endod 2010;36:157-9.