Fracture strength of roots instrumented with three different single file systems in curved root canals

ABSTRACT

Objective: The aim of this study was to compare the fracture strength of roots instrumented with three different single file rotary systems in curved mesial root canals of maxillary molars. Materials and Methods: Curvatures of 25°–35° on mesial roots of 60 maxillary molar teeth were sectioned below the cementoenamel junction to obtain roots 11 mm in length. The roots were balanced with respect to buccolingual and mesiodistal diameter and weight. They were distributed into three experimental groups and one control group (no instrumentation) (n = 15): Reciproc rotary file (R25, VDW, Munich, Germany), WaveOne Primary rotary file (Dentsply Tulsa Dental Specialties, Tulsa, UK) and OneShape (Micro-Mega, Besancon, France) rotary file. Vertical load was applied until fracture occurred. Data were statistically analyzed using one-way analysis of variance test (P < 0.05). Results: The mean fracture load was 412 ± 72 Newton (N) for the control group, 395 ± 69 N for the Reciproc group, 373 ± 63 N for the WaveOne group and 332 ± 68 N for the OneShape group. The fracture load differences among three experimental groups were not statistically significant (P > 0.05.) Whereas, the fracture loads of control and OneShape groups were significantly different (P = 0.012). Conclusions: Fracture resistance of the roots instrumented with WaveOne and Reciproc file systems were similar to the control group whereas it was observed that OneShape rotary file systems enhance the fracture strength of standardized curved roots when compared with the control group.

Key words:

Curved root - fracture resistance - root fracture - single file systems

 

Conflict of Interest

None declared.

• REFERENCES

• 1 Tang W, Wu Y, Smales RJ. Identifying and reducing risks for potential fractures in endodontically treated teeth. J Endod 2010; 36: 609-17
• 2 Karapinar KazandagM, Sunay H, Tanalp J, Bayirli G. Fracture resistance of roots using different canal filling systems. Int Endod J 2009; 42: 705-10
• 3 Capar ID, Altunsoy M, Arslan H, Ertas H, Aydinbelge HA. Fracture strength of roots instrumented with self-adjusting file and the ProTaper rotary systems. J Endod 2014; 40: 551-4
• 4 Shemesh H, Bier CA, Wu MK, Tanomaru-Filho M, Wesselink PR. The effects of canal preparation and filling on the incidence of dentinal defects. Int Endod J 2009; 42: 208-13
• 5 Cobankara FK, Ungör M, Belli S. The effect of two different root canal sealers and smear layer on resistance to root fracture. J Endod 2002; 28: 606-9
• 6 Testori T, Badino M, Castagnola M. Vertical root fractures in endodontically treated teeth: A clinical survey of 36 cases. J Endod 1993; 19: 87-91
• 7 Lam PP, Palamara JE, Messer HH. Fracture strength of tooth roots following canal preparation by hand and rotary instrumentation. J Endod 2005; 31: 529-32
• 8 Kim HC, Lee MH, Yum J, Versluis A, Lee CJ, Kim BM. Potential relationship between design of nickel-titanium rotary instruments and vertical root fracture. J Endod 2010; 36: 1195-9
• 9 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
• 10 Glossen CR, Haller RH, Dove SB, del Rio CE. A comparison of root canal preparations using Ni-Ti hand, Ni-Ti engine-driven, and K-Flex endodontic instruments. J Endod 1995; 21: 146-51
• 11 Guelzow A, Stamm O, Martus P, Kielbassa AM. Comparative study of six rotary nickel-titanium systems and hand instrumentation for root canal preparation. Int Endod J 2005; 38: 743-52
• 12 Ankrum MT, Hartwell GR, Truitt JE. K3 Endo, ProTaper, and ProFile systems: Breakage and distortion in severely curved roots of molars. J Endod 2004; 30: 234-7
• 13 Park H. A comparison of Greater Taper files, ProFiles, and stainless steel files to shape curved root canals. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2001; 91: 715-8
• 14 Chakka NV, Ratnakar P, Das S, Bagchi A, Sudhir S, Anumula L. Do NiTi instruments show defects before separation?. Defects caused by torsional fatigue in hand and rotary nickel-titanium (NiTi) instruments which lead to failure during clinical use. J Contemp Dent Pract 2012; 13: 867-72
• 15 Bhatti N, Sroa R, Sikri VK. Evaluation of surface preparation and maintenance of canal curvature following instrumentation with hand ‘K’ file and three different Ni-Ti rotary systems: A radiographic and SEM study. Contemp Clin Dent 2010; 1: 88-93
• 16 Shay B, Moshonov J. Single file endodontic treatment: A new era?. Refuat Hapeh Vehashinayim 2013; 30: 6-9 76
• 17 Al-Hadlaq SM, Aljarbou FA, AlThumairy RI. Evaluation of cyclic flexural fatigue of M-wire nickel-titanium rotary instruments. J Endod 2010; 36: 305-7
• 18 da Frota MF, Espir CG, Berbert FL, Marques AA, Sponchiado-Junior EC, Tanomaru-Filho M. et al. Comparison of cyclic fatigue and torsional resistance in reciprocating single-file systems and continuous rotary instrumentation systems. J Oral Sci 2014; 56: 269-75
• 19 Roane JB, Sabala CL, Duncanson Jr MG. The “balanced force” concept for instrumentation of curved canals. J Endod 1985; 11: 203-11
• 20 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
• 21 Yoldas O, Yilmaz S, Atakan G, Kuden C, Kasan Z. Dentinal microcrack formation during root canal preparations by different NiTi rotary instruments and the self-adjusting file. J Endod 2012; 38: 232-5
• 22 Hin ES, Wu MK, Wesselink PR, Shemesh H. Effects of self-adjusting file, Mtwo, and ProTaper on the root canal wall. J Endod 2013; 39: 262-4
• 23 Schneider SW. A comparison of canal preparations in straight and curved root canals. Oral Surg Oral Med Oral Pathol 1971; 32: 271-5
• 24 Ertas H, Sagsen B, Arslan H, Er O, Ertas ET. Effects of physical and morphological properties of roots on fracture resistance. Eur J Dent 2014; 8: 261-4
• 25 You SY, Kim HC, Bae KS, Baek SH, Kum KY, Lee W. Shaping ability of reciprocating motion in curved root canals: A comparative study with micro-computed tomography. J Endod 2011; 37: 1296-300
• 26 Capar ID, Ertas H, Ok E, Arslan H. Comparison of single cone obturation performance of different novel nickel-titanium rotary systems. Acta Odontol Scand 2014; 72: 537-42
• 27 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
• 28 Adorno CG, Yoshioka T, Jindan P, Kobayashi C, Suda H. The effect of endodontic procedures on apical crack initiation and propagation ex vivo . Int Endod J 2013; 46: 763-8
• 29 Priya NT, Chandrasekhar V, Anita S, Tummala M, Raj TB, Badami V. et al. “Dentinal microcracks after root canal preparation” a comparative evaluation with hand, rotary and reciprocating instrumentation. J Clin Diagn Res 2014; 8: ZC70-2