title: Bonding of resin composite to carbon dioxide laser-modified human enamel.
abstract: OBJECTIVE
  Irradiation of enamel with carbon dioxide (CO2) laser energy alters physical and chemical properties of the enamel surface, and these lasers hold promise for conditioning enamel for bonding of adhesive restorations. This laboratory study examined the influence of laser irradiation parameters on the shear bond strength obtained for laser etching using a hybrid composite.
  
  
  METHODS
  Standardized surfaces prepared on 110 non-carious intact extracted anterior teeth were exposed to CO2 laser energy (9 different laser exposure parameters) or etched with orthophosphoric acid.
  
  
  RESULTS
  Laser treatment under defined conditions (power density 2380 W/cm2, energy density 23.8 J/cm2) resulted in a bond strength of 30.0 +/- 4.7 MPa, which exceeded that obtained for acid etching (17.9 +/- 4.3 MPa, p < 0.0001). Cohesive failure occurred within the bonding resin in this group.
  
  
  CONCLUSIONS
  These data indicate that CO2 laser etching may enhance the bonding of resin composite to human enamel.
authors.affiliation: Department of Dentistry, University of Queensland Dental School, Brisbane, Australia.
authors.forename: L J
authors.initials: LJ
authors.lastname: Walsh
authors.forename: D
authors.initials: D
authors.lastname: Abood
authors.forename: P J
authors.initials: PJ
authors.lastname: Brockhurst
mesh_terms: D000134:Acid Etching, Dental; D002245:Carbon Dioxide; D003188:Composite Resins; D001840:Dental Bonding / Q000379:methods*; D003743:Dental Enamel / Q000528:radiation effects*; D006801:Humans; D007834:Lasers; D008422:Materials Testing; D019279:Resin Cements; D013499:Surface Properties; D013718:Tensile Strength
chemical_list: D003188:Composite Resins; D019279:Resin Cements; C067788:scotchbond 2; D002245:Carbon Dioxide