title: Selective ablation of orthodontic composite by using sub-microsecond IR laser pulses with optical feedback.
abstract: OBJECTIVE
  Conventional methods of residual composite removal after debonding orthodontic brackets involve the use of abrasives that damage the underlying enamel. The objective of this study was to determine whether infrared pulsed lasers are suitable for the removal of composite through selective laser ablation.
  
  
  METHODS
  Pulsed CO(2) and Er:YAG lasers were evaluated for their ability to selectively ablate orthodontic composites. Optical emission spectra of the luminous plasma produced during composite and enamel ablation were acquired to differentiate between enamel and composite ablation to minimize accidental removal of enamel.
  
  
  RESULTS
  TEA CO(2) laser pulses at a wavelength of 10.6 microm were best suited for the selective ablation of composite. Spectral analysis of plume emission identified several calcium emission lines that can potentially be used to distinguish between enamel and composite ablation.
  
  
  CONCLUSIONS
  TEA CO(2) lasers operating at 10.6 microm used in conjunction with optical feedback have the potential to selectively ablate residual dental composite and minimize inadvertent removal of enamel.
authors.affiliation: Department of Growth and Development, University of California, San Francisco, California 94143, USA.
authors.forename: T
authors.initials: T
authors.lastname: Dumore
authors.forename: D
authors.initials: D
authors.lastname: Fried
mesh_terms: D002245:Carbon Dioxide; D003738:Dental Cements; D017005:Dental Debonding / Q000379:methods*; D003743:Dental Enamel / Q000293:injuries*; D004871:Erbium; D006801:Humans; D066298:In Vitro Techniques; D007259:Infrared Rays; D053685:Laser Therapy; D009970:Orthodontics / Q000379:methods*; D014072:Tooth Abrasion / Q000517:prevention & control*
chemical_list: D003738:Dental Cements; D002245:Carbon Dioxide; D004871:Erbium