Evaluation of dentin defect formation during retreatment with hand and rotary instruments: A micro-CT study

Ayca Yilmaz, Dilek Helvacioglu-Yigit, Cansu Gur, Handan Ersev, Gullu Kiziltas Sendur, Egemen Avcu, Canan Baydemir, Paul Vincent Abbott

Research output: Contribution to journalArticlepeer-review

9 Citations (Scopus)


The purpose of this study was to compare the incidence and longitudinal propagation of dentin defects after gutta-percha removal with hand and rotary instruments using microcomputed tomography. Twenty mandibular incisors were prepared using the balanced-force technique and scanned in a 19.9 μmresolution. Following filling with the lateral compaction technique, gutta-percha was removed with ProTaper Universal Retreatment (PTUR) or hand instruments. After rescanning, a total of 24,120 cross-sectional images were analyzed. The numbers, types, and longitudinal length changes of defects were recorded. Defects were observed in 36.90% of the cross sections. A total of 73 defects were comprised of 87.67% craze lines, 2.73% partial cracks, and 9.58% fractures. No significant difference in terms of new defect formation was detected between the retreatment groups. The apical and middle portions of the roots had more dentin defects than the coronal portions. Defects in three roots of the PTUR instrument group increased in length. Under the conditions of this in vitro study, gutta-percha removal seemed to not increase the incidence of dentin defect formation, but the longitudinal defect propagation finding suggests possible cumulative dentinal damage due to additional endodontic procedures. Hand and rotary instrumentation techniques caused similar dentin defect formation during root canal retreatment.

Original languageEnglish
Article number4868603
Pages (from-to)1-7
Number of pages7
Publication statusPublished - 24 May 2017


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