title: Polarized light and scanning electron microscopic investigation of enamel hypoplasia in primary teeth.
abstract: BACKGROUND
  Enamel hypoplasia is a developmental disturbance during enamel formation, defined as a macroscopic defect in the enamel, with a reduction of the enamel thickness with rounded, smooth borders. Information on the microstructural level is still limited, therefore further studies are of importance to better understand the mechanisms behind enamel hypoplasia.
  
  
  OBJECTIVE
  To study enamel hypoplasia in primary teeth by means of polarized light microscopy and scanning electron microscopy.
  
  
  METHODS
  Nineteen primary teeth with enamel hypoplasia were examined in a polarized light microscope and in a scanning electron microscope.
  
  
  RESULTS
  The cervical and incisal borders of the enamel hypoplasia had a rounded appearance, as the prisms in the rounded cervical area of the hypoplasia were bent. The rounded borders had a normal surface structure whereas the base of the defects appeared rough and porous.
  
  
  CONCLUSIONS
  Morphological findings in this study indicate that the aetiological factor has a short duration and affects only certain ameloblasts. The bottom of the enamel hypoplasia is porous and constitutes possible pathways for bacteria into the dentin.
authors.affiliation: Department of Pediatric Dentistry, Institute of Odontology, Sahlgrenska Academy, University of Gothenburg, Göteborg, Sweden. nina.sabel@vgregion.se
authors.forename: Nina
authors.initials: N
authors.lastname: Sabel
authors.forename: Gunilla
authors.initials: G
authors.lastname: Klingberg
authors.forename: Wolfram
authors.initials: W
authors.lastname: Dietz
authors.forename: Sandor
authors.initials: S
authors.lastname: Nietzsche
authors.forename: Jörgen G
authors.initials: JG
authors.lastname: Norén
mesh_terms: D000565:Ameloblasts / Q000473:pathology; D003743:Dental Enamel / Q000473:pathology / Q000648:ultrastructure; D003744:Dental Enamel Hypoplasia / Q000473:pathology*; D003804:Dentin / Q000473:pathology / Q000648:ultrastructure; D006801:Humans; D008855:Microscopy, Electron, Scanning; D008859:Microscopy, Polarization; D016062:Porosity; D016628:Replica Techniques; D014094:Tooth, Deciduous / Q000473:pathology* / Q000648:ultrastructure