title: Periapical Microsurgery: Can Ultrasonic Root-end Preparations Clinically Create or Propagate Dentinal Defects?
abstract: BACKGROUND
  This clinical study evaluates the effect of ultrasonic root-end preparations on dentinal defect creation and propagation.
  
  
  METHODS
  Eighty-four teeth were treated with periapical microsurgery using a modern microsurgical protocol in a private practice setting. The root apices were resected and inspected for dentinal defects with a surgical operating microscope and a 0.8-mm diameter light-emitting diode microscope diagnostic probe light, both before and after ultrasonic root-end preparations. A 3-grade scale (none, partial, and full dentinal defect) was used to assess the status of the roots before and after ultrasonic root-end preparation.
  
  
  RESULTS
  Of the 84 treated teeth, 3 had a vertical root fracture, leaving a total of 81 teeth for assessment. Fifty-one teeth were intact upon resection and remained intact after root-end preparation. Twenty-six teeth had partial dentinal defects, and 14 (54%) of these propagated into full dentinal defects after root-end preparation.
  
  
  CONCLUSIONS
  This periapical microsurgery study showed that ultrasonic root-end preparations are safe to use on intact roots. Preexisting dentinal defects can be propagated by ultrasonic root-end preparations. Through the use of light-emitting diodes, dentinal defects can be detected, special root-end management can be implemented, and more predictable outcomes may be achieved.
authors: Department of Endodontics, UNC School of Dentistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina. Electronic address: pzt@unc.edu.
authors: Peter Z
authors: PZ
authors: Tawil
mesh_terms: D000328:Adult; D003804:Dentin / Q000293:injuries*; D005260:Female; D006801:Humans; D008297:Male; D008866:Microsurgery / Q000009:adverse effects* / Q000295:instrumentation / Q000379:methods*; D018915:Root Canal Preparation / Q000295:instrumentation / Q000379:methods; D019227:Tooth Apex / Q000000981:diagnostic imaging / Q000601:surgery*; D016896:Treatment Outcome; D014464:Ultrasonic Therapy / Q000009:adverse effects* / Q000379:methods*
keywords: Dentinal defect; endodontic microsurgery; fracture; root-end preparation; ultrasonics