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Updated: Jun 2, 2026
Scanning Electron Microscopic Evaluation of Surface Defects of Remover Retreatment File After Single and Multiple Uses
Published on: October 11, 2024
Removal of broken files from root canals by using ultrasonic techniques combined with dental microscope: a
Mei Fu1, Zhiling Zhang, Benxiang Hou
1Department of Endodontics, Capital Medical University, Beijing, China.
Introduction:
The objective of this study was to assess the clinical outcome after removal of a broken file from root canal by using ultrasonic techniques and to evaluate various factors that might influence the outcome.
Methods:
One hundred two patients with 102 teeth with a broken file in the root canal, treated between 2004 and 2008, were contacted for follow-up examination 12-68 months after treatment (median, 28 months). Outcome was assessed on the basis of clinical and radiographic criteria by calibrated examiners and dichotomized as healed or disease. The result was analyzed statistically by Pearson or Fisher exact test and multivariate logistic regression.
Results:
Of 66 teeth examined (64.7% recall), 81.8% were healed. Stepwise logistic regression analysis revealed that inadequate root canal filling was a statistically significant factor in predicting failure of successful healing. The cases with removal of broken files had a higher healing rate than those with broken files left in the root canal, but the difference was not statistically significant (P > .05). There was no significant difference in outcome related to presence or absence of perforation, although the rate of healing was greater in teeth without perforation. Other factors including age, sex, tooth type, apical status, position of segment, and type of restoration did not affect prognosis.
Conclusions:
Treatment outcome after the use of ultrasonics for removal of broken files was favorable. Adequate root filling has a more substantial impact on treatment outcome than the other factors.