title: Quality of root-end preparations using ultrasonic and rotary instrumentation in cadavers.
abstract: Prior investigations have demonstrated dentinal cracking and chipping during ultrasonic preparation of the root-end. This study compared the frequency of cracking and chipping in two groups, cadaver and extracted teeth, using an indirect resin technique. Preparations were performed using either a 33 1/2 inverted cone bur in a high-speed handpiece, or with ultrasonics using a CT-2 tip at either high or low intensity. After replication of the root-end in epoxy resin, all teeth were evaluated for cracking and chipping under scanning electron microscopy. Statistical analysis using a general contingency table or ANOVA with Scheffé post-hoc analysis (p = 0.05) revealed no significant difference between all groups in terms of root-end cracking. In extracted teeth (n = 15), rotary instrumentation produced less chipping than either ultrasonic technique. Varying the intensity was not significant. There was no significant difference between any instrumentation group in cadaver teeth (n = 10) related to the amount of chipping.
authors.affiliation: Department of Applied Dental Medicine, Southern Illinois University School of Dental Medicine, 2800 College Avenue, Alton, IL 62002-4798, USA.
authors.forename: G J
authors.initials: GJ
authors.lastname: Gray
authors.forename: J F
authors.initials: JF
authors.lastname: Hatton
authors.forename: D J
authors.initials: DJ
authors.lastname: Holtzmann
authors.forename: D B
authors.initials: DB
authors.lastname: Jenkins
authors.forename: C J
authors.initials: CJ
authors.lastname: Nielsen
mesh_terms: D000704:Analysis of Variance; D001047:Apicoectomy; D002102:Cadaver; D004396:Coloring Agents; D003754:Dental High-Speed Equipment; D003804:Dentin / Q000293:injuries / Q000473:pathology; D004853:Epoxy Resins; D004867:Equipment Design; D006801:Humans; D008751:Methylene Blue; D008855:Microscopy, Electron, Scanning; D015588:Observer Variation; D016628:Replica Techniques; D018915:Root Canal Preparation / Q000295:instrumentation / Q000592:standards*; D014092:Tooth Root / Q000293:injuries / Q000473:pathology*; D014464:Ultrasonic Therapy / Q000295:instrumentation*
chemical_list: D004396:Coloring Agents; D004853:Epoxy Resins; D008751:Methylene Blue