title: Microstructure and mineral composition of dental enamel of permanent and deciduous teeth.
abstract: OBJECTIVE
  This study evaluated and compared in vitro the microstructure and mineral composition of permanent and deciduous teeth's dental enamel.
  
  
  METHODS
  Sound third molars (n = 12) and second primary molars (n = 12) were selected and randomly assigned to the following groups, according to the analysis method performed (n = 4): Scanning electron microscopy (SEM), X-Ray diffraction (XRD) and Energy dispersive X-ray spectrometer (EDS). Qualitative and quantitative comparisons of the dental enamel were done. The microscopic findings were analyzed statistically by a nonparametric test (Kruskal-Wallis). The measurements of the prisms number and thickness were done in SEM photomicrographs. The relative amounts of calcium (Ca) and phosphorus (P) were determined by EDS investigation. Chemical phases present in both types of teeth were observed by the XRD analysis.
  
  
  RESULTS
  The mean thickness measurements observed in the deciduous teeth enamel was 1.14 mm and in the permanent teeth enamel was 2.58 mm. The mean rod head diameter in deciduous teeth was statistically similar to that of permanent teeth enamel, and a slightly decrease from the outer enamel surface to the region next to the enamel-dentine junction was assessed. The numerical density of enamel rods was higher in the deciduous teeth, mainly near EDJ, that showed statistically significant difference. The percentage of Ca and P was higher in the permanent teeth enamel.
  
  
  CONCLUSIONS
  The primary enamel structure showed a lower level of Ca and P, thinner thickness and higher numerical density of rods.
authors: Department of Pediatric Dentistry, Dental School of Uberaba, University of Uberaba, Uberaba, Minas Gerais, Brazil.
authors: Maria Angélica Hueb
authors: MA
authors: De Menezes Oliveira
authors: Carolina Paes
authors: CP
authors: Torres
authors: Jaciara Miranda
authors: JM
authors: Gomes-Silva
authors: Michelle Alexandra
authors: MA
authors: Chinelatti
authors: Fernando Carlos Hueb
authors: FC
authors: De Menezes
authors: Regina Guenka
authors: RG
authors: Palma-Dibb
authors: Maria Cristina
authors: MC
authors: Borsatto
mesh_terms: D003743:Dental Enamel / Q000737:chemistry* / Q000648:ultrastructure*; D006801:Humans; D008855:Microscopy, Electron, Scanning; D008903:Minerals / Q000032:analysis; D013052:Spectrometry, X-Ray Emission; D014070:Tooth / Q000737:chemistry* / Q000648:ultrastructure*; D014961:X-Ray Diffraction
chemical_list: D008903:Minerals