title: Effect of a pulsed CO2 laser and fluoride on the prevention of enamel and dentine erosion.
abstract: OBJECTIVE
  The hypotheses of this study was that pulsed CO(2) laser (lambda=10.6 microm) treatment in combination (or not) with previous fluoride gel application could increase the resistance of enamel and dentine to erosion, throughout successive erosive challenges.
  
  
  METHODS
  Thirty-two bovine specimens of enamel and of root dentine were flattened, polished and randomly assigned to the following treatments (n=8): fluoride (F), laser (L), fluoride+laser (FL) or no treatment as negative control (C). The treated specimens were submitted to demineralization (0.3% citric acid, pH 2.45, for 5 min) and remineralization (artificial saliva, for 60 min) cycles, three times a day, for 3 days. Dental surface loss as well as the concentration of calcium, phosphorus and fluoride in the demineralizing solutions were determined after each cycling day. Enamel and dentine were analysed separately using repeated measures ANOVA for ranks (alpha=0.05).
  
  
  RESULTS
  The association between fluoride and laser (FL) resulted in the lowest enamel and dentine surface loss values throughout the cycles, differing significantly from the control group. No clear benefit of FL over the F or L treatments was observed. There was a non-significant trend (p>0.05) for FL to release less calcium, phosphorus and fluoride into the demineralizing solutions when compared to the other groups.
  
  
  CONCLUSIONS
  Pulsed CO(2) laser (lambda=10.6 microm) alone was not able to prevent enamel or dentine surface losses due to erosion. Laser treatment in combination with fluoride showed some protection, but the effect does not appear to be synergistic.
authors.affiliation: Department of Pediatric Dentistry, Piracicaba Dental School, State University of Campinas - UNICAMP, Av. Limeira, 901 - Piracicaba, SP 13414-903, Brazil.
authors.forename: Carolina
authors.initials: C
authors.lastname: Steiner-Oliveira
authors.forename: Marinês
authors.initials: M
authors.lastname: Nobre-dos-Santos
authors.forename: Domenick T
authors.initials: DT
authors.lastname: Zero
authors.forename: George
authors.initials: G
authors.lastname: Eckert
authors.forename: Anderson T
authors.initials: AT
authors.lastname: Hara
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D002118:Calcium / Q000032:analysis; D002417:Cattle; D003743:Dental Enamel / Q000187:drug effects* / Q000528:radiation effects*; D003804:Dentin / Q000187:drug effects* / Q000528:radiation effects*; D005459:Fluorides / Q000008:administration & dosage / Q000032:analysis / Q000494:pharmacology*; D005782:Gels; D054020:Lasers, Gas; D010758:Phosphorus / Q000032:analysis; D011897:Random Allocation; D017001:Tooth Demineralization; D014077:Tooth Erosion / Q000517:prevention & control*; D014089:Tooth Remineralization
chemical_list: D005782:Gels; D010758:Phosphorus; D005459:Fluorides; D002118:Calcium