Laser-activated fluoride treatment of enamel against an artificial caries challenge: comparison of five wavelengths.
BACKGROUND
Laser-activated fluoride (LAF) therapy with 488 nm laser energy has been shown previously to increase the resistance of human enamel and dentine to acid dissolution in laboratory models of dental caries. The aims of this study were to examine whether LAF therapy, conducted using a range of wavelengths in the visible and near infrared regions, can protect human dental enamel from an artificial cariogenic challenge.


METHODS
Buccal and lingual surfaces of extracted sound, molar and premolar teeth were used to prepare matched pairs of enamel slabs (N=10 per group). After application of neutral sodium fluoride gel (12300 ppm F ion), slab surfaces were lased (energy density 15 J/cm2; spot size 5mm, wavelength 532, 633, 670, 830 or 1064nm), then exposed to an artificial cariogenic challenge for a period of seven days. The Vicker's hardness number (VHN) was recorded before and after laser treatment and again following the cariogenic challenge. Negative controls did not receive laser exposure.


RESULTS
All wavelengths of laser light examined provided an effective LAF effect, compared with the unlased negative control surfaces.


CONCLUSIONS
Using this in vitro model, we conclude that the action spectrum of the LAF effect extends across the visible and near-infrared regions of the spectrum.
School of Dentistry, The University of Queensland, Brisbane.
J
J
Vlacic
I A
IA
Meyers
J
J
Kim
L J
LJ
Walsh
D000538:Aluminum Silicates; D001151:Arsenic; D002327:Cariostatic Agents / Q000627:therapeutic use*; D016022:Case-Control Studies; D003731:Dental Caries / Q000473:pathology / Q000517:prevention & control*; D003743:Dental Enamel / Q000187:drug effects / Q000528:radiation effects* / Q000648:ultrastructure; D003747:Dental Enamel Solubility / Q000187:drug effects / Q000528:radiation effects; D005708:Gallium; D005782:Gels; D006244:Hardness; D006801:Humans; D053685:Laser Therapy; D007834:Lasers / Q000145:classification; D009354:Neodymium; D012969:Sodium Fluoride / Q000627:therapeutic use*; D015019:Yttrium
D000538:Aluminum Silicates; D002327:Cariostatic Agents; D005782:Gels; D009354:Neodymium; D015019:Yttrium; D012969:Sodium Fluoride; D005708:Gallium; D001151:Arsenic