title: Powder emission rates of four air polishing devices.
abstract: OBJECTIVE
  Although highly effective in plaque and stain removal, the use of air polishing devices (APDs) on denuded root surfaces may lead to clinically relevant loss of tooth substance. As the amount of powder emitted by an APD may have a significant impact on the safety and efficacy of the instruments, the purpose of the study was to quantify the amount of powder emitted by APDs depending on their powder filling status and powder setting.
  
  
  METHODS
  Four different APDs were filled to maximum level and the cumulative amount of powder emitted, depending on instrument settings and filling status, was quantified during 15 subsequent 120-s periods of use. Differences in powder emission were analyzed using anova repeated measures.
  
  
  RESULTS
  Exact powder dosage was possible in one APD only (Dentsply Prophyjet) where emission rates also remained constant over the first five periods assessed. In the three other APDs assessed (EMS Air-Flow, Satellec Air-Max, KaVo Prophyflex II powder emission depended on the amount of powder present in the powder chamber and declined with ongoing use. Changes in powder setting had a significant impact on powder emission in all APDs assessed, apart from the KaVo Prophyflex II unit.
  
  
  CONCLUSIONS
  Powder emission of APDs may vary greatly depending on the amount of powder present in the powder bowl. Therefore, instrument powder setting may not be a reliable parameter for safety and efficacy adjustments. This should be considered in clinical applications as well as in future research.
authors.affiliation: Clinic for Periodontology, University of Münster, Private Practice, Düsseldorf, Germany. peterslk@uni-muenster.de
authors.forename: Gregor J
authors.initials: GJ
authors.lastname: Petersilka
authors.forename: Ulf
authors.initials: U
authors.lastname: Schenck
authors.forename: Thomas F
authors.initials: TF
authors.lastname: Flemmig
mesh_terms: D020906:Air Abrasion, Dental / Q000295:instrumentation*; D000704:Analysis of Variance; D003754:Dental High-Speed Equipment; D012534:Dental Scaling / Q000295:instrumentation*; D004869:Equipment Safety; D011208:Powders; D015203:Reproducibility of Results; D017693:Sodium Bicarbonate
chemical_list: D011208:Powders; D017693:Sodium Bicarbonate