title: Effect of diode laser and fluoride varnish on initial surface demineralization of primary dentition enamel: an in vitro study.
abstract: BACKGROUND
  Previous investigations have demonstrated improved enamel caries resistance after laser irradiation. The purpose of this in vitro study was to assess the caries-preventive potential of 809 nm diode laser treatment of the enamel of primary teeth compared to topical fluoride application.
  
  
  METHODS
  Eighty samples of sound primary teeth were embedded in plastic and stored in saline solution. The enamel surface of 80 samples was polished in an area of 2 x 2 mm. These tooth specimens were randomly assigned to one control and three test groups: (1) no treatment/control; (2) application of 0.1 mg of fluoride varnish (Duraphat) for 6 h; (3) diode laser application (809 nm, 140 mJ, 50 Hz, Ø 600 micro m fibre, contact mode, absorber, 1 min; ORA-LASER01 I.S.T.); and (4) combined application - laser/fluoride varnish. Caries-like lesions were created by pH-cycling. After lesion formation, longitudinal sections were taken and examined by polarized light microscopy.
  
  
  RESULTS
  In the control group, all samples showed lesions up to 30 micro m in depth. After laser application, lesions could be identified in 15 out of 20 samples. Topical fluoride treatment in groups 2 (varnish) and 4 (laser/varnish) completely inhibited the development of caries-like lesions in all samples.
  
  
  CONCLUSIONS
  In this in vitro investigation, topical fluoride treatment enhances the resistance of sound enamel of primary teeth more effectively than diode laser application.
authors.affiliation: Department of Dentistry, Faculty of Dentistry, University of São Paulo, São Paulo, Brazil.
authors.forename: M R L A
authors.initials: MR
authors.lastname: Santaella
authors.forename: A
authors.initials: A
authors.lastname: Braun
authors.forename: E
authors.initials: E
authors.lastname: Matson
authors.forename: M
authors.initials: M
authors.lastname: Frentzen
mesh_terms: D016009:Chi-Square Distribution; D003131:Combined Modality Therapy; D003733:Dental Caries Susceptibility / Q000187:drug effects / Q000528:radiation effects; D003743:Dental Enamel / Q000187:drug effects / Q000473:pathology / Q000528:radiation effects*; D005460:Fluorides, Topical / Q000627:therapeutic use*; D006801:Humans; D053685:Laser Therapy; D008859:Microscopy, Polarization; D012969:Sodium Fluoride / Q000627:therapeutic use; D017001:Tooth Demineralization / Q000473:pathology / Q000517:prevention & control*; D014094:Tooth, Deciduous / Q000187:drug effects / Q000473:pathology / Q000528:radiation effects*
chemical_list: D005460:Fluorides, Topical; C023807:sodium fluoride topical preparation; D012969:Sodium Fluoride