title: Physical and compositional changes on demineralized primary enamel induced by CO2 Laser.
abstract: OBJECTIVE
  This in vitro study aimed to evaluate the physical and chemical changes promoted by a CO(2) laser at 10.6-microm wavelength on primary dental enamel with artificial caries-like lesions.
  
  
  BACKGROUND
  Several previous investigations have shown that enamel can be modified by CO(2) laser to obtain a caries-preventive effect, but the specific mechanism remains uncertain.
  
  
  METHODS
  Twenty-seven primary molars were randomly assigned to three groups as follows: control, carious, and laser (n = 9). The specimens from the carious and laser groups were demineralized and treated with or without CO(2) laser, according to the group. Enamel surface changes after treatments were monitored using Fourier transform Raman spectroscopy and scanning electron microscopy (SEM).
  
  
  RESULTS
  The Raman spectra showed a statistically significant reduction of mineral content in carious and laser groups when compared to control group. Additionally, carbonate content was reduced in irradiated specimens when compared to the other groups. No physical change was observed in specimens evaluated by SEM.
  
  
  CONCLUSIONS
  The results suggest that CO(2) laser irradiation may reduce the carbonate content of enamel, which is likely to make this substrate more acid-resistant.
authors: Faculty of Dentistry of Piracicaba, State University of Campinas, Piracicaba, SP, Brazil.
authors: Elaine Pereira
authors: EP
authors: da Silva Tagliaferro
authors: Lidiany Karla Azevedo
authors: LK
authors: Rodrigues
authors: Luís Eduardo Silva
authors: LE
authors: Soares
authors: Airton Abrahão
authors: AA
authors: Martin
authors: Marinês
authors: M
authors: Nobre-dos-Santos
mesh_terms: D002254:Carbonates / Q000032:analysis; D002648:Child; D003731:Dental Caries / Q000517:prevention & control* / Q000532:radiotherapy; D003743:Dental Enamel / Q000737:chemistry / Q000528:radiation effects*; D005583:Fourier Analysis; D006801:Humans; D053685:Laser Therapy; D054020:Lasers, Gas; D028022:Low-Level Light Therapy; D008855:Microscopy, Electron, Scanning; D013059:Spectrum Analysis, Raman; D017001:Tooth Demineralization
chemical_list: D002254:Carbonates