title: Cutting characteristics of a sonic root-end preparation instrument.
abstract: The aim of this study was to investigate the cutting ability of retro tips powered by a sonic handpiece (MM 1500, Micro Mega, Prodonta, Geneva, Switzerland). Two levels of the following variables were evaluated in this study: a) power setting with the an inlet ring half or fully open, b) orientation of tip perpendicular or parallel to the long axis of the handpiece, c) length of tip 2 or 3 min, d) loading of 25 or 50 grams, e) tip size 35 or 55. The substrate used was 1 mm thick sections of bovine bone and load was controlled by using a load cell interfaced with a transducer meter. Instrumentation time was fixed at 10 seconds with water irrigation. A 2(5) full factorial analysis was performed with two replications making a total of 64 experimental units. The resultant depth of cut was measured using a stereo microscope at x50 magnification. Analysis of the data indicated that all variables had a significant effect on cutting (ANOVA p < 0.05). The most significant factor was power, followed by tip length tip orientation, width and load. An increase in loading resulted in tip constraint and a reduction of cutting at the lower power setting. In conclusion sonically activated retro tips were found to cut satisfactorily with instrument air inlet ring opening/power having the main effect.
authors.affiliation: School of Manufacturing and Mechanical Engineering, University of Birmingham, England.
authors.forename: R
authors.initials: R
authors.lastname: Devall
authors.forename: P J
authors.initials: PJ
authors.lastname: Lumley
authors.forename: M
authors.initials: M
authors.lastname: Waplington
authors.forename: L
authors.initials: L
authors.lastname: Blunt
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D002417:Cattle; D003762:Dental Instruments; D004867:Equipment Design; D005069:Evaluation Studies as Topic; D005269:Femur; D012184:Retrograde Obturation / Q000295:instrumentation*; D018915:Root Canal Preparation / Q000295:instrumentation*; D013010:Sonication / Q000295:instrumentation