title: Abrasiveness of an air-powder polishing system on root surfaces in vitro.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the abrasiveness of a new air polisher on root surfaces.
  
  
  METHODS
  Fifty extracted human teeth were air polished for 5 seconds.
  
  
  RESULTS
  All root surfaces showed a circular defect visible with the naked eye. Scanning electron microscope examination showed smooth crater walls and a few open dentin tubules, but most seemed to be obliterated. Laser profilometry of the exposed areas revealed defects with an average depth of 484 microns, whereas the unexposed root surfaces showed irregularities with an average depth of 323 microns. The depths of the abraded areas were evaluated in relation to the values for the unexposed surfaces, and an average depth of 161 microns was found. The difference between the exposed and unexposed surfaces was statistically significant.
  
  
  CONCLUSIONS
  The present study indicates that the air polisher has a strong abrading effect on exposed root surfaces and should therefore be used with caution on patients with gingival retractions.
authors.affiliation: Department of Dental Pathology, Operative Dentistry, and Endodontics, Royal Dental College, Faculty of Health Sciences, University of Aarhus, Vennelyst Boulevard 9, DK 8000 Aarhus C, Denmark.
authors.forename: M S
authors.initials: MS
authors.lastname: Agger
authors.forename: P
authors.initials: P
authors.lastname: Hörsted-Bindslev
authors.forename: O
authors.initials: O
authors.lastname: Hovgaard
mesh_terms: D020906:Air Abrasion, Dental / Q000009:adverse effects* / Q000295:instrumentation*; D003804:Dentin / Q000293:injuries; D006801:Humans; D007834:Lasers; D008855:Microscopy, Electron, Scanning; D013499:Surface Properties; D014075:Tooth Discoloration / Q000628:therapy; D014092:Tooth Root / Q000293:injuries*