title: Evaluation of the breakage of orthograde endodontic ultrasonic tips.
abstract: BACKGROUND
  The objective of this study was to compare the breakage of 3 endodontic ultrasonic tips when removing dentin from extracted molars.
  
  
  METHODS
  Three tips were tested (n = 10): BUC 1A (Obtura Spartan, Fenton, MO), CPR 5D (Obtura Spartan), and EDS 5E (Essential Dental Systems, South Hackensack, NJ). Extracted molars were prepared and mounted to a slow-speed alternating-current motor of a custom testing apparatus, which provided a 5-mm linear movement at an approximate rate of 4 mm/s. A 20-g axial force was applied to the tooth specimens. The MiniEndo II Ultrasonic Unit (SybronEndo, Orange, CA) was used to operate the ultrasonic tips in 20-second cycles with 10 seconds of rest between each cycle. The process was repeated until breakage was observed or 10 minutes had elapsed. The time to breakage was recorded for each sample. Tips that did not break were assigned a breakage time of 10 minutes.
  
  
  RESULTS
  There was a statistically significant difference in breakage as a function of tip type (P = .0002). No EDS 5E tips were observed to break after 10 minutes of instrumentation.
  
  
  CONCLUSIONS
  Based on the results of the investigation, the EDS 5E tip is significantly more resistant to breakage than the other tips tested.
authors.affiliation: Essential Dental Laboratories, South Hackensack, New Jersey. Electronic address: jwan@edsdental.com.
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Wan
authors.affiliation: Essential Dental Laboratories, South Hackensack, New Jersey.
authors.forename: Allan S
authors.initials: AS
authors.lastname: Deutsch
authors.affiliation: Essential Dental Laboratories, South Hackensack, New Jersey.
authors.forename: Barry L
authors.initials: BL
authors.lastname: Musikant
authors.affiliation: Essential Dental Laboratories, South Hackensack, New Jersey.
authors.forename: Jason
authors.initials: J
authors.lastname: Guzman
mesh_terms: D003804:Dentin / Q000648:ultrastructure; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006801:Humans; D008422:Materials Testing; D018915:Root Canal Preparation / Q000295:instrumentation*; D013314:Stress, Mechanical; D013499:Surface Properties; D013997:Time Factors; D014464:Ultrasonic Therapy / Q000295:instrumentation*
keywords: Breakage; endodontics; ultrasonic tips