title: Protective effect of fluoride varnish and fluoride gel on enamel erosion: roughness, SEM-EDS, and µ-EDXRF studies.
abstract: OBJECTIVE
  The effects of fluoride treatment on bovine enamel subjected to acid erosion were studied by roughness (Ra) measurements, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and microenergy-dispersive X-ray fluorescence spectrometry (μ-EDXRF).
  
  
  METHODS
  Enamel samples (63) were divided into nine groups (n = 7): artificial saliva (AS), Pepsi Twist(®) (PT), orange juice (OJ), Duraphat(®)  + Pepsi Twist(®) (DPH/PT), Duraphat(®)  + orange juice (DPH/OJ), Duofluorid(®)  + Pepsi Twist(®) (DUO/PT), Duofluorid(®)  + orange juice (DUO/OJ), fluoride gel + Pepsi Twist(®) (FG/PT), and fluoride gel + orange juice (FG/OJ). Fluoride was applied and the samples were submitted to six cycles (demineralization: Pepsi Twist(®) or orange juice, 10 min; remineralization: saliva, 1 h). The enamel surface in depth was exposed and 63 line-scan maps were performed.
  
  
  RESULTS
  The elemental analysis by EDS revealed that only fluoride treated groups had any detectable fluorine after erosion cycles (DPH/PT: 3.50 wt%; DPH/OJ: 3.37 wt%; DUO/PT: 2.69 wt%; DUO/OJ: 3.54 wt%; FG/PT: 2.17 wt%; FG/OJ: 2.77 wt%). PT treatment resulted in significantly higher Ra values than the artificial saliva (P < 0.001). Scanning electron microscopy (SEM) analysis of fluoride protected enamel showed areas with some globular structures or a residual layer of varnish. The enamel thickness was significantly lower in PT (0.63 ± 0.087 mm) than in DPH/PT (0.87 ± 0.16 mm) and DUO/PT (0.92 ± 0.14 mm) groups (P < 0.01).
  
  
  CONCLUSIONS
  Fluoride treatments protected enamel without Ra increase and loss of enamel tissue.
authors: Dental Materials and Operative Dentistry Department, School of Dentistry, Research and Development Institute, IP&D, Laboratory of Biomedical Vibrational Spectroscopy, Universidade do Vale do Paraíba, UNIVAP, LEVB, São José dos Campos, São Paulo, Brazil.
authors: Luís Eduardo Silva
authors: LE
authors: Soares
authors: Antonio Carlos Belfort
authors: AC
authors: De Carvalho Filho
mesh_terms: D000143:Acids / Q000633:toxicity*; D000818:Animals; D002417:Cattle; D003729:Dental Care / Q000379:methods; D003743:Dental Enamel / Q000187:drug effects*; D005459:Fluorides / Q000494:pharmacology*; D005782:Gels / Q000008:administration & dosage; D008855:Microscopy, Electron, Scanning; D010150:Paint; D013052:Spectrometry, X-Ray Emission; D013499:Surface Properties / Q000187:drug effects*; D014077:Tooth Erosion / Q000517:prevention & control*; D016896:Treatment Outcome
chemical_list: D000143:Acids; D005782:Gels; D005459:Fluorides
keywords: beverages; dental erosion; energy-dispersive X-ray fluorescence spectrometry; fluoride varnish; roughness; scanning electron microscopy