title: Effects of curet and ultrasonics on root surfaces.
abstract: OBJECTIVE
  To compare the effect on root surfaces of three ultrasonic scalers to each other and to a periodontal curet.
  
  
  METHODS
  Forty extracted teeth were washed and embedded in acrylic resin leaving one entire coronal-apical tooth aspect exposed. The teeth were divided between four treatments: piezoelectric A - Group A, piezoelectric B - Group B, magnetostrictive - Group C, hand instrumentation with a curet - Group D. A single experienced operator simulated clinical instrumentation over a 9 mm square area on each tooth until the surface was judged smooth by the operator. Three evaluations were used in the study: (1) root tracings with a surface roughness meter to determine the roughness average (Ra) and roughness maximum (Rmax) in microns, (2) use of a new EXD 11/12 explorer to assess planed roots and (3) visual evaluation of the root surfaces through a stereoscopic microscope (X 20). During examinations 2 and 3, root surfaces were assigned to one of four "smoothness categories" by the examiners. Data for evaluation 1 was analyzed by ANOVA. Data from evaluations 2 and 3 were analyzed using the Kruskal-Wallis non-parametric test.
  
  
  RESULTS
  The mean Ra and Rmax were not significantly different between the four groups. The results from both clinicians' examinations showed a significant difference in the four groups (P=0.001). The curet produced the smoothest surfaces, the two piezoelectric instruments produced the next smoothest surface and the magnetostrictive instrument the least smooth root surfaces.
authors.affiliation: UCHSC School of Dentistry, Department of Dental Hygiene, Denver, CO 80262, USA.
authors.forename: G N
authors.initials: GN
authors.lastname: Cross-Poline
authors.forename: D J
authors.initials: DJ
authors.lastname: Stach
authors.forename: S M
authors.initials: SM
authors.lastname: Newman
mesh_terms: D000704:Analysis of Variance; D005069:Evaluation Studies as Topic; D006801:Humans; D008280:Magnetics; D016745:Root Planing / Q000295:instrumentation* / Q000379:methods; D018709:Statistics, Nonparametric; D013357:Subgingival Curettage / Q000295:instrumentation; D013499:Surface Properties; D014092:Tooth Root / Q000473:pathology; D014464:Ultrasonic Therapy / Q000295:instrumentation*