title: Subgingival instrumentation to remove simulated plaque in vitro: influence of operators' experience and type of instrument.
abstract: BACKGROUND
  There is uncertainty regarding the benefits and risks of hand versus powered root surface instrumentation. Moreover, the influence of operators' experience on treatment results is unclear. We compared newly developed sonic, ultrasonic and hand instruments, hypothesizing that powered devices allow to remove more simulated plaque in less time than hand instruments, with significant influence of operators' experience.
  
  
  METHODS
  Sonic scaler (AIR), ultrasonic scaler (TIG) device and double Gracey curettes (GRA) were utilized by seven experienced operators (EOs) and four less experienced operators (LOs) in periodontitis manikin heads. The time required for treatment, the proportion of residual-simulated plaque and the weight loss caused by scaling as a proxy for root surface destruction were measured.
  
  
  RESULTS
  Using different instruments led to significantly different proportions of removed simulated plaque regardless of operators' experience (AIR, 80.2 ± 21.3 %, TIG, 69.9 ± 22.5 %, GRA, 73.1 ± 20.0 %) (p < 0.001). Treatment times did not significantly differ between EO and LO (p > 0.05). Weight loss was increased when using hand instead of powered instruments (p < 0.001), with significantly higher weight loss induced by LO than EO (p = 0.004).
  
  
  CONCLUSIONS
  Within the present study, EO did not remove more simulated plaque in less time but induced less root surface destruction. Using a sonic device was most beneficial for plaque removal.
  
  
  CONCLUSIONS
  Successful root surface debridement requires both time and training regardless of the used instrument. Hand instruments might cause more damage to root surfaces, especially in the hands of less experienced operators.
authors.affiliation: Clinic of Conservative Dentistry and Periodontology, University of Kiel, Kiel, Germany, graetz@konspar.uni-kiel.de.
authors.forename: Christian
authors.initials: C
authors.lastname: Graetz
authors.forename: Falk
authors.initials: F
authors.lastname: Schwendicke
authors.forename: Anna
authors.initials: A
authors.lastname: Plaumann
authors.forename: Sebastian
authors.initials: S
authors.lastname: Rauschenbach
authors.forename: Claudia
authors.initials: C
authors.lastname: Springer
authors.forename: Maren
authors.initials: M
authors.lastname: Kahl
authors.forename: Sonja
authors.initials: S
authors.lastname: Sälzer
authors.forename: Christof E
authors.initials: CE
authors.lastname: Dörfer
mesh_terms: D002983:Clinical Competence; D003762:Dental Instruments; D003773:Dental Plaque / Q000628:therapy*; D012534:Dental Scaling / Q000295:instrumentation*; D004867:Equipment Design; D006801:Humans; D066298:In Vitro Techniques; D008348:Manikins; D014092:Tooth Root