title: Morphologic changes following in vitro CO2 laser treatment of calculus-ladened root surfaces.
abstract: OBJECTIVE
  The purpose of this study was to compare morphologic changes following C02 laser or manual curette treatment of calculus-ladened tooth root surfaces.
  
  
  METHODS
  Laser treatment consisted of repeated single passes with a 6 Watt focused beam at 20 pulses per second, a pulse length of 0.01 second, and a manufacturer's laser efficiency rating of 86% (i.e., the amount of total power delivered through the aperture). The rate of beam passage over the target surface was controlled at 4 mm/second using an 0.8 mm diameter tip. The calculated energy density was 240 J/cm2 for each pass of the beam. Scaled and root planed surfaces were treated with a standardized force of 600 grams using new curettes. Specimens were evaluated by scanning electron microscopy.
  
  
  RESULTS
  Laser-induced surface changes included charring, meltdown and resolidification of calculus mineral, and ablation of microbial plaque. Laser-treated specimens also exhibited residual calculus and microbial plaque deposits in areas directly adjacent to the beam path. Scaled and root planed surfaces featured smooth and/or scale like smear layers and islands of residual calculus and microbial plaque.
  
  
  CONCLUSIONS
  The rough surface topography resulting from laser treatment and residual calculus and microbial plaque deposits indicates that C02 laser treatment of exposed root surfaces is, at best, an adjunct to traditional methods of therapy.
authors.affiliation: Department of Periodontics, University of Missouri-Kansas City, MO, USA.
authors.forename: D
authors.initials: D
authors.lastname: Tucker
authors.forename: C M
authors.initials: CM
authors.lastname: Cobb
authors.forename: J W
authors.initials: JW
authors.lastname: Rapley
authors.forename: W J
authors.initials: WJ
authors.lastname: Killoy
mesh_terms: D003728:Dental Calculus / Q000532:radiotherapy* / Q000628:therapy / Q000648:ultrastructure; D003739:Dental Cementum / Q000528:radiation effects / Q000648:ultrastructure; D003773:Dental Plaque / Q000532:radiotherapy / Q000628:therapy / Q000648:ultrastructure; D012534:Dental Scaling; D006801:Humans; D066298:In Vitro Techniques; D053685:Laser Therapy; D008855:Microscopy, Electron, Scanning; D016745:Root Planing; D014092:Tooth Root / Q000528:radiation effects / Q000648:ultrastructure