Evaluation of Radicular Dentin Microcracks Formation after Instrumentation with NiTi Hand and Rotary File System: A Stereomicroscopic Study
Shalan Kaul, Feby Kuriakose, Jittin James, Basil Joy, Reema Malik
Hand files, Nickel–titanium files, Stereomicroscope,Dentin microcracks
Citation Information :
Kaul S, Kuriakose F, James J, Joy B, Malik R. Evaluation of Radicular Dentin Microcracks Formation after Instrumentation with NiTi Hand and Rotary File System: A Stereomicroscopic Study. J Contemp Dent Pract 2020; 21 (11):1233-1237.
Aim and objective: The present study aimed to assess the formation of microcracks in root dentin post-instrumentation with nickel–titanium (NiTi) hand and rotary file system.
Materials and methods: Totally, 80 freshly extracted mandibular premolar teeth with single roots were chosen for this study. Access opening was performed and #10 K-file was used to attain patency of canal. All specimens were divided into four groups (each group having 20 specimens), i.e., Group I: Unprepared, Group II: NiTi hand K-files, Group III: Self-adjusting file, and Group IV: XP-Shaper single file. Complete irrigation of all the canals was performed after instrumentation. All roots were cut horizontally at three levels [apical third (3 mm), middle third (6 mm), and cervical third (9 mm)] from the apex with diamond disc. A stereomicroscope was used to view the sections under 20× magnification.
Results: Self-adjusting file showed least number of defects with a percentage of 75% followed by XP-Shaper and NiTi hand K-files with a values of 65 and 60%, respectively. Use of hand K-files resulted in greater number of incomplete cracks (30%) and use of XP-Shaper demonstrated greater number of craze lines (15%). A statistically significant difference was found between the experimental groups in the formation of dentinal defects of root at apical third (3 mm) (p < 0.031) and middle third (6 mm) (p < 0.001), whereas the sections at cervical third (9 mm) did not show any statistically significant difference (p > 0.312).
Conclusion: The present study concluded that the self-adjusting file system gives promising better results in cleaning ability with minimal incidence of radicular dentin microcracks than XP-Shaper and NiTi hand K-files system.
Clinical significance: The root dentin may unavoidably get damaged during instrumentation resulting in the formation of dentinal cracks and tiny complicated fractures, thus leading to endodontic failures. Various factors cause dentinal cracks, but the flexibility of file due to heat treatment, kinematics of the file, and the basic architecture of the file are the most significant ones. Self-adjusting file system represented satisfactory results with minimal microcracks defects.
Song YL, Bian Z, Fan B, et al. A comparison of instrument-centering ability within the root canal for three contemporary instrumentation techniques. Int Endod J 2004;37(4):265–271. DOI: 10.1111/j.0143-2885.2004.00798.x.
Thompson SA. An overview of nickel-titanium alloys used in dentistry. Int Endod J 2000;33(4):297–310. DOI: 10.1046/j.1365-2591.2000.00339.x.
Pujari H. Stress distribution of new generation of twisted files in comparison with ProTaper: a finite element analysis. Saudi Endod J 2013;3(2):65–69. DOI: 10.4103/1658-5984.118149.
Peters OA. Current challenges and concepts in the preparation of root canal systems: a review. J Endod 2004;30(8):559–567. DOI: 10.1097/01.DON.0000129039.59003.9D.
Yoshino K, Ito K, Kuroda M, et al. Prevalence of vertical root fracture as the reason for tooth extraction in dental clinics. Clin Oral Investig 2015;19(6):1405–1409. DOI: 10.1007/s00784-014-1357-4.
Barreto MS, MoraesRdo A, Rosa RA, et al. Vertical root fractures and dentin defects: effects of root canal preparation, filling and mechanical cycling. J Endod 2012;38(8):1135–1139. DOI: 10.1016/j.joen.2012.05.002.
Amitha M, Adarsha MS, Meena N, et al. Comparative assessment of formation of dentin microcracks after root canal preparation using hand, rotary, and reciprocating instrumentation - an in vitro study. Int J Oral Care Res 2018;6(2):S19–S23.
Yoldas O, Yilmaz S, Atakan G, et al. Dentinal microcrack formation during root canal preparations by different NiTi rotary instruments and the self-adjusting file. J Endod 2012;38(2):232–235. DOI: 10.1016/j.joen.2011.10.011.
Langaliya AK, Kothari AK, Surti NR, et al. In vitro comparative evaluation of dentinal microcracks formation during root canal preparation by different nickel-titanium file systems. Saudi Endod J 2018;8:183–188.
Bier CAS, Shemesh H, Tanomaru-Filho M, et al. The ability of different nickel-titanium rotary instruments to induce dentinal damage during canal preparation. J Endod 2009;35(2):236–238. DOI: 10.1016/j.joen.2008.10.021.
Ashwinkumar V, Krithikadatta J, Surendran S, et al. Effect of reciprocating file motion on microcrack formation in root canals: an SEM study. Int Endod J 2014;47(7):622–627. DOI: 10.1111/iej.12197.
Kubo M, Miura J, Sakata T, et al. Structural modifications of dentinal microcracks with human aging. Microscopy (Oxf) 2013;62(6):555–561.
Mohammed MN, Kamel WH, Rokaya ME. Comparison of the cleaning effectiveness and incidence of dentinal defects after biomechanical preparation using different ni ti rotary instruments in root canals. ADJ 2020;7(2):165–170.
Versiani M, Souza E, De-Deus G. Critical appraisal of studies on dentinal radicular microcracks in endodontics: methodological issues, contemporary concepts, and future perspectives. Endod Topics 2015;33(1):87–156. DOI: 10.1111/etp.12091.
Hof R, Perevalov V, Eltanani M, et al. The self-adjusting file (SAF). part 2: mechanical analysis. J Endod 2010;36(4):691–696. DOI: 10.1016/j.joen.2009.12.028.
Peters OA, Paque F. Root canal preparation of maxillary molars with self-adjusting file: a micro-computed tomography study. J Endod 2011;37(1):53–57. DOI: 10.1016/j.joen.2010.08.047.
Carlesi T, Nigro G, Di Giacomo L, et al. Dentinal microcrack formation during root canal treatment with Mtwo instruments and MicroSeal filling technique. J Adv Oral Res 2018;9(1-2):31–37. DOI: 10.1177/2320206818801260.
Nazari A, Bajaj D, Zhang D, et al. Aging and the reduction in fracture toughness of human dentin. J Mech Behav Biomed Mater 2009;2(5):550–559.
Bajaj D, Sundaram N, Nazari A, et al. Age, dehydration and fatigue crack growth in dentin. Biomaterials 2006;27(11):2507–2517. DOI: 10.1016/j.biomaterials.2005.11.035.