title: Enamel crystals of mice susceptible or resistant to dental fluorosis: an AFM study.
abstract: OBJECTIVE
  This study aimed to assess the overall apatite crystals profile in the enamel matrix of mice susceptible (A/J strain) or resistant (129P3/J strain) to dental fluorosis through analyses by atomic force microscopy (AFM).
  
  
  METHODS
  Samples from the enamel matrix in the early stages of secretion and maturation were obtained from the incisors of mice from both strains. All detectable traces of matrix protein were removed from the samples by a sequential extraction procedure. The purified crystals (n=13 per strain) were analyzed qualitatively in the AFM. Surface roughness profile (Ra) was measured.
  
  
  RESULTS
  The mean (±SD) Ra of the crystals of A/J strain (0.58±0.15 nm) was lower than the one found for the 129P3/J strain (0.66±0.21 nm) but the difference did not reach statistical significance (t=1.187, p=0.247). Crystals of the 129P3/J strain (70.42±6.79 nm) were found to be significantly narrower (t=4.013, p=0.0013) than the same parameter measured for the A/J strain (90.42±15.86 nm).
  
  
  CONCLUSIONS
  enamel crystals of the 129P3/J strain are narrower, which is indicative of slower crystal growth and could interfere in the occurrence of dental fluorosis.
authors.affiliation: Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Bauru, SP, Brazil.
authors.forename: Marília Afonso Rabelo
authors.initials: MA
authors.lastname: Buzalaf
authors.affiliation: Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Bauru, SP, Brazil.
authors.forename: Carolina Silveira
authors.initials: CS
authors.lastname: Barbosa
authors.affiliation: Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Bauru, SP, Brazil.
authors.forename: Aline de Lima
authors.initials: Ade L
authors.lastname: Leite
authors.affiliation: Department of Cariology, Restorative Sciences and Endodontics, University of Michigan School of Dentistry, U.S.A.
authors.forename: Sywe-Ren
authors.initials: SR
authors.lastname: Chang
authors.affiliation: Department of Cariology, Restorative Sciences and Endodontics, University of Michigan School of Dentistry, U.S.A.
authors.forename: Jun
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Conservative Dentistry and Periodontics, Poznan University of Medical Sciences, Poland.
authors.forename: Agata
authors.initials: A
authors.lastname: Czajka-Jakubowska
authors.affiliation: Department of Conservative Dentistry and Periodontics, Poznan University of Medical Sciences, Poland.
authors.forename: Brian
authors.initials: B
authors.lastname: Clarkson
mesh_terms: D000818:Animals; D001031:Apatites / Q000032:analysis*; D003460:Crystallization; D003743:Dental Enamel / Q000737:chemistry / Q000648:ultrastructure*; D005459:Fluorides / Q000009:adverse effects; D009050:Fluorosis, Dental / Q000209:etiology* / Q000503:physiopathology; D008297:Male; D051379:Mice; D057507:Mice, 129 Strain; D008805:Mice, Inbred A; D018625:Microscopy, Atomic Force; D013499:Surface Properties; D014867:Water / Q000737:chemistry
chemical_list: D001031:Apatites; D014867:Water; D005459:Fluorides