title: Histological and profilometric evaluation of the root surface after instrumentation with a new piezoelectric device - ex vivo study.
abstract: OBJECTIVE
  An ex vivo model was designed to profilometrically and histologically assess root changes resulting from scaling with a new ultrasonic device, designed for bone piezoelectric surgery, in comparison with curettes.
  
  
  METHODS
  Three groups of 10 periodontal hopeless teeth were each subjected to different root instrumentation: Gracey curettes (CUR); ultrasonic piezoelectric device, Perio 100% setting, level 8 (P100); and ultrasonic piezoelectric device Surg 50% setting, level 1 (S50). After extraction, all teeth were photographed to visually assess the presence of dental calculus. The treated root surfaces were profilometrically evaluated (Ra, Rz, Rmax). Undecalcified histological sections were prepared to assess qualitative changes in cementum thickness. Statistical analysis was carried out using one-way anova test with a significance level of 95%.
  
  
  RESULTS
  Both instruments proved to be effective in the complete removal of calculus. The CUR group presented the lowest Ra [2.28 μm (±0.58)] and S50 the highest [3.01 μm (±0.61)]. No statistically significant differences were detected among the three groups, for Ra, Rz and Rmax. Histologically, there was a cementum thickness reduction in all groups, being higher and more irregular in S50 group.
  
  
  CONCLUSIONS
  Within the limits of this study, there were no statistically significant differences in roughness parameters analyzed between curettes and the ultrasonic piezoelectric unit. This new instrument removes a smaller amount of cementum, mainly at the Perio 100% power setting, which appears to be the least damaging. The ultrasonic device is effective in calculus removal, proving to be as effective as curettes.
authors.affiliation: Faculty of Medicine, Department of Dentistry, University of Coimbra, Coimbra, Portugal.
authors.forename: D
authors.initials: D
authors.lastname: Silva
authors.forename: O
authors.initials: O
authors.lastname: Martins
authors.forename: S
authors.initials: S
authors.lastname: Matos
authors.forename: P
authors.initials: P
authors.lastname: Lopes
authors.forename: T
authors.initials: T
authors.lastname: Rolo
authors.forename: I
authors.initials: I
authors.lastname: Baptista
mesh_terms: D000368:Aged; D055113:Chronic Periodontitis / Q000150:complications; D003728:Dental Calculus / Q000473:pathology / Q000628:therapy; D003739:Dental Cementum / Q000473:pathology; D012534:Dental Scaling / Q000295:instrumentation*; D003804:Dentin / Q000473:pathology; D004867:Equipment Design; D019220:High-Energy Shock Waves / Q000627:therapeutic use*; D006801:Humans; D008875:Middle Aged; D010514:Periodontal Pocket / Q000150:complications; D010781:Photography / Q000379:methods; D059745:Piezosurgery / Q000295:instrumentation; D016745:Root Planing / Q000295:instrumentation*; D013357:Subgingival Curettage / Q000295:instrumentation; D014092:Tooth Root / Q000473:pathology*
keywords: curettes; dental calculus; non-surgical periodontal debridement; periodontal hand instrumentation; piezoelectric instrumentation