title: Morphological and compositional alterations of in vivo aged prefabricated pediatric metal crowns (PMCs).
abstract: OBJECTIVE
  The purpose of the present study was to assess the morphological and elemental alterations of retrieved prefabricated metal crowns (PMCs) after intraoral exposure.
  
  
  METHODS
  Seventeen in vivo aged stainless steel crowns (3M ESPE) were collected. The intraoral exposure time varied from 3 to 101 months. For every retrieved crown one new crown of the same type was used as a reference. The reference and in vivo aged crowns were examined by high-vacuum scanning electron microscopy and energy-dispersive X-ray microanalysis. The elemental composition between the as-received and in vivo aged crowns was statistically analyzed by t-test (a=0.05).
  
  
  RESULTS
  In vivo aged crown surfaces demonstrated significantly morphological alterations with accumulation of amorphous intraoral integuments, biting imprints, wear and occlusal perforations. The results of microanalysis showed that there were no statistically significant differences in the elemental composition of the stainless steel crowns between the two conditions.
  
  
  CONCLUSIONS
  Under the conditions of the present study, retrieved prefabricated pediatric stainless steel crowns exhibit morphological changes mainly due to plastic deformation, without changes in elemental composition.
authors.affiliation: Department of Biomaterials, School of Dentistry, University of Athens, Thivon 2, Goudi 11527, Athens, Greece. szinelis@dent.uoa.gr
authors.forename: Spiros
authors.initials: S
authors.lastname: Zinelis
authors.forename: Tina
authors.initials: T
authors.lastname: Lambrinaki
authors.forename: Katerina
authors.initials: K
authors.lastname: Kavvadia
authors.forename: Lisa
authors.initials: L
authors.lastname: Papagiannoulis
mesh_terms: D002648:Child; D002857:Chromium / Q000737:chemistry; D003442:Crowns; D003722:Dental Alloys / Q000737:chemistry*; D003741:Dental Deposits / Q000737:chemistry; D019554:Dental Restoration Wear / Q000145:classification; D004577:Electron Probe Microanalysis; D006801:Humans; D007501:Iron / Q000737:chemistry; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D009055:Mouth / Q000502:physiology*; D009532:Nickel / Q000737:chemistry; D013193:Stainless Steel / Q000737:chemistry*; D013499:Surface Properties; D013997:Time Factors
chemical_list: D003722:Dental Alloys; D002857:Chromium; D013193:Stainless Steel; D009532:Nickel; D007501:Iron