Title

Dentin loss and fracture resistance after ultrasonic retrieval of separated NiTi instruments

Authors

Dhruval Acharya¹, Lavanshi Mishra², Jasmine Marwaha³,*, Suchismita Chakraborty⁴, Vipin
Arora⁵ & Deepankar Dass⁶

Affiliation

¹Department of Oral and Maxillofacial Pathology, K. M. Shah Dental College and Hospital, Sumandeep Vidyapeeth Deemed to be University, Gujarat, India; ²Department of Conservative Dentistry and Endodontics, Modern Dental College and Research Centre, Indore, India; ³Department of Conservative Dentistry and Endodontics, National Dental College and Hospital, Derabassi, Punjab, India; ⁴Department of Conservative Dentistry and Endodontics, Guwahati, Assam, India; ⁵Department of Restorative Dental Sciences, Faculty of Dentistry, Taif University, Taif, Kingdom of Saudi Arabia; ⁶Department of Conservative Dentistry & Endodontics, Maharishi Markandeshwar College of Dental Sciences & Research, Mullana, Haryana, India; *Corresponding author

Email

Dhruval Acharya - E-mail: acharyadhruval@gmail.com
Lavanshi Mishra - E-mail: lavanshi.mishra910@gmail.com
Jasmine Marwaha - E-mail: drjasminemarwaha@gmail.com
Suchismita Chakraborty - E-mail: smita2025mds@gmail.com
Vipin Arora - E-mail: vipinendodontist@gmail.com
Deepankar Dass - E-mail: deepankardass@gmail.com

Article Type

Research Article

Date

Received September 1, 2026; Revised September 30, 2026; Accepted September 30, 2026, Published September 30, 2026
 

Abstract

Retrieval of separated nickel-titanium instruments may preserve endodontic treatment options, but excessive dentin removal can weaken the root and reduce fracture resistance. This in vitro study used micro-computed tomography and universal testing machine analysis to compare dentin loss and fracture resistance after retrieval with different ultrasonic retrieval systems. Eighty extracted single-rooted mandibular premolars with standardized root dimensions were allocated to conventional ultrasonic tip, micro ultrasonic tip, and loop-assisted ultrasonic retrieval and control groups. Retrieval success was highest with loop-assisted ultrasonic retrieval (90.0%), while dentin volume loss was lowest with micro-ultrasonic tips (3.8 ± 1.1 mm³) and fracture resistance was significantly reduced after conventional ultrasonic retrieval compared with controls (412.6 ± 84.7 N vs 586.4 ± 92.3 N; p<0.001). Thus, ultrasonic retrieval systems differed significantly in dentin preservation and post-retrieval fracture resistance, supporting the need for conservative retrieval protocols guided by three-dimensional assessment.

Keywords

Micro-CT, separated instrument, ultrasonic retrieval, nickel-titanium file, dentin loss, fracture resistance, endodontics

Citation

Acharya et al. Bioinformation 22(9): 5547-5551 (2026)

Edited by

Ashwini Dhopte

ISSN

0973-2063

Publisher

Biomedical Informatics

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.