title: Comparison of ultrasonic and high-speed-bur root-end preparations using bilaterally matched teeth.
abstract: The purpose of this study was to compare ultrasonic and high-speed-bur root-end preparations. Seventy-six roots from 29 bilaterally matched pairs of human teeth in cadavers were used in this study. In group 1 ultrasonic preparations were made in 38 roots and filled with amalgam. In group 2 high-speed bur preparations were made in 38 roots and filled with amalgam. The size of the bony crypt was measured and the teeth were extracted and radiographed mesial-distally and buccal-lingually. None of the root-end preparations resulted in root perforation. The mean mesial-distal minimum depth of ultrasonic and high-speed bur preparations were 2.11 mm and 1.39 mm, respectively. The mean buccal-lingual minimum depth of preparation was 2.51 mm for the ultrasonic and 2.05 mm for the high-speed bur preparations. The depth of the ultrasonic preparations was significantly greater for both measurements. A significantly greater bevel angle was associated with the bur preparations, 35.1 degrees versus 16.0 degrees for the ultrasonic preparations. The incidence of ultrasonic root-end preparations deviating from the uninstrumented canal spaces was found to be 2.6%. All bur root-end preparations were at an acute angle to the long axis of the root. The bony crypt size for bur preparations was significantly greater than that for ultrasonic preparations.
authors.affiliation: Department of Endodontics, OHSU School of Dentistry, Portland 97201, USA.
authors.forename: D S
authors.initials: DS
authors.lastname: Mehlhaff
authors.forename: J G
authors.initials: JG
authors.lastname: Marshall
authors.forename: J C
authors.initials: JC
authors.lastname: Baumgartner
mesh_terms: D002102:Cadaver; D003481:Cuspid / Q000000981:diagnostic imaging; D003754:Dental High-Speed Equipment / Q000706:statistics & numerical data; D005069:Evaluation Studies as Topic; D006801:Humans; D008437:Maxilla; D011859:Radiography; D018915:Root Canal Preparation / Q000295:instrumentation* / Q000379:methods / Q000706:statistics & numerical data; D014464:Ultrasonic Therapy / Q000295:instrumentation* / Q000706:statistics & numerical data