title: Bactericidal efficacy of carbon dioxide laser against bacteria-contaminated titanium implant and subsequent cellular adhesion to irradiated area.
abstract: OBJECTIVE
  The aim of this study was to assess CO2 laser ability to eliminate bacteria from titanium implant surfaces. The changes of the surface structure, the rise in temperature, and the damage of connective tissue cells after laser irradiation were also considered.
  
  
  METHODS
  Streptococcus sanguis and Porphyromonas gingivalis on titanium discs were irradiated by an expanded beam of CO2 laser. Surface alteration was observed by a light, and a scanning electron, microscope. Temperature was measured with a thermograph. Damage of fibroblastic (L-929) and osteoblastic (MC3T3-E1) cells outside the irradiation spot and adhesion of the cells to the irradiated area were also estimated.
  
  
  RESULTS
  All the organisms (10(8)) of S. sanguis and P. gingivalis were killed by the irradiation at 286 J/cm2 and 245 J/cm2, respectively. Furthermore, laser irradiation did not cause surface alteration, rise of temperature, serious damage of connective tissue cells located outside the irradiation spot, or inhibition of cell adhesion to the irradiated area.
  
  
  CONCLUSIONS
  CO2 laser irradiation with expanded beam may be useful in removing bacterial contaminants from implant surface.
authors.affiliation: Department of Fixed Prosthodontics, School of Dentistry, Niigata University, Japan. taku@dent.niigata-u.ac.jp
authors.forename: T
authors.initials: T
authors.lastname: Kato
authors.forename: H
authors.initials: H
authors.lastname: Kusakari
authors.forename: E
authors.initials: E
authors.lastname: Hoshino
mesh_terms: D000818:Animals; D002448:Cell Adhesion / Q000528:radiation effects; D002460:Cell Line; D002470:Cell Survival / Q000528:radiation effects; D003722:Dental Alloys / Q000528:radiation effects*; D015921:Dental Implants / Q000382:microbiology*; D004866:Equipment Contamination / Q000517:prevention & control*; D005347:Fibroblasts / Q000502:physiology / Q000528:radiation effects; D007834:Lasers; D051379:Mice; D008855:Microscopy, Electron, Scanning; D010006:Osteoblasts / Q000502:physiology / Q000528:radiation effects; D016966:Porphyromonas gingivalis / Q000528:radiation effects*; D013298:Streptococcus sanguis / Q000528:radiation effects*; D013499:Surface Properties; D013696:Temperature; D014025:Titanium / Q000528:radiation effects*
chemical_list: D003722:Dental Alloys; D015921:Dental Implants; D014025:Titanium