title: In vitro investigation of fluorescence of carious dentin observed with a Soprolife® camera.
abstract: OBJECTIVE
  Our aim was to determine the origin of the red fluorescence of carious dentine observed with the Soprolife® camera.
  
  
  METHODS
  We conducted in vitro studies to evaluate the origin of the red fluorescence using acids and matrix metalloproteinase (MMP) to mimic caries and methylglycoxal (MGO) to evaluate the effect of glycation reactions on the red fluorescence. In every step of these models, we detected the changes of dentin photonic response with Soprolife® in daylight mode and in treatment mode. A Raman spectroscopy analysis was performed to determine the variations of the dentin organic during the in vitro caries processes. Raman microscopy was performed to identify change in the collagen matrix of dentine.
  
  
  RESULTS
  The red fluorescence observed in carious dentine using a Soprolife® camera corresponds to the brownish color observed using daylight. Demineralization using nitric acid induces a loss of the green fluorescence of dentine. The red fluorescence of carious dentine is resistant to acid treatment. Immersion of demineralized dentine in MGO induces a change of color from white to orange-red. This indicates that the Maillard reaction contributes to lesion coloration. Immersion of demineralized dentine in an MMP-1 solution followed by MGO treatment results in a similar red fluorescence. Raman microspectroscopy analysis reveals accumulation of AGE's product in red-colored dentine.
  
  
  CONCLUSIONS
  Our results provide important information on the origin of the fluorescence variation of dentine observed with the Soprolife® camera. We demonstrate that the red fluorescence of carious dentine is linked to the accumulation of Advanced Glycation End products (AGE).
  
  
  CONCLUSIONS
  The study provides a new biological basis for the red fluorescence of carious dentine and reinforces the importance of the Soprolife® camera in caries diagnostics.
authors.affiliation: EA4203 Laboratory of Biology and Nano-science, Université Montpellier 1, Montpellier, France.
authors.forename: Ivan
authors.initials: I
authors.lastname: Panayotov
authors.forename: Elodie
authors.initials: E
authors.lastname: Terrer
authors.forename: Hamideh
authors.initials: H
authors.lastname: Salehi
authors.forename: Hervé
authors.initials: H
authors.lastname: Tassery
authors.forename: Jacques
authors.initials: J
authors.lastname: Yachouh
authors.forename: Frédéric J G
authors.initials: FJ
authors.lastname: Cuisinier
authors.forename: Bernard
authors.initials: B
authors.lastname: Levallois
mesh_terms: D003094:Collagen / Q000737:chemistry; D003731:Dental Caries / Q000175:diagnosis / Q000473:pathology*; D003804:Dentin / Q000737:chemistry / Q000473:pathology*; D005453:Fluorescence; D017127:Glycation End Products, Advanced / Q000032:analysis; D006801:Humans; D015416:Maillard Reaction; D020781:Matrix Metalloproteinase 1; D023861:Photography, Dental / Q000295:instrumentation; D013059:Spectrum Analysis, Raman
chemical_list: D017127:Glycation End Products, Advanced; D003094:Collagen; D020781:Matrix Metalloproteinase 1