Title
Root dentin microcrack formation using hand and rotary files: An in vitro comparative study
Authors
Akanksha Kumari*, Ajay Kumar Nagpal, Anupama Pradhan, Arunima Jana, Seemran Panda & Astha Bhargava
Affiliation
Department of Conservative Dentistry and Endodontics, K.D. Dental College and Hospital, Mathura, Uttar Pradesh, India; *Corresponding author
Akanksha Kumari - E-mail: akki212022@gmail.com
Ajay Kumar Nagpal - E-mail: drajayendodontist@gmail.com
Anupama Pradhan - E-mail: pradhananu37@gmail.com
Arunima Jana - E-mail: arunimajana1998@gmail.com
Seemran Panda - E-mail: seemranpanda4@gmail.com
Astha Bhargava - E-mail: asthabhargava03@gmail.com
Article Type
Research Article
Date
Received July 1, 2026; Revised July 31, 2026; Accepted July 31, 2026, Published July 31, 2026
Abstract
Dentinal microcracks during root canal instrumentation pose a serious risk by weakening root structure and predisposing teeth to vertical root fractures. Therefore, it is of interest to compare the incidence of dentinal microcracks produced by HyFlex CM rotary file system, HanuDent Blue rotary file system, NT Rainbow S rotary file system and conventional hand K-files in extracted premolars under standardized conditions. Fifty specimens were prepared, sectioned at 2, 4 and 6 mm and evaluated under a stereomicroscope with defects scored and analyzed using the chi-square test (p ≤ 0.05). Results showed that hand K-files produced the least dentinal damage, while rotary systems especially HyFlex CM and HanuDent Blue generated significantly more microcracks, with NT Rainbow S performing comparatively better among rotary instruments. Thus, data show that file design and metallurgy significantly influence dentinal preservation, supporting the selection of safer instrumentation systems in endodontic practice.
Keywords
Dentinal microcracks, biomechanical preparation, rotary file systems, hand k-files root dentine integrity
Citation
Kumari et al. Bioinformation 22(7): 4370-4374 (2026)
Edited by
Ritik Kashwani
ISSN
0973-2063
Publisher
License
This is an Open Access article which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. This is distributed under the terms of the Creative Commons Attribution License.
