title: MicroCT study on the enamel mineral density of primary molars.
abstract: OBJECTIVE
  The aim of this study is to report on the mineral density of the enamel of primary molars related to the age of the child and to compare the mineral density of sound and carious enamel in those molars.
  
  
  METHODS
  This study included 23 children and 41 extracted primary molars. The primary molars of 21 children met all of the inclusion criteria, and these were studied and scanned using microCT. The teeth were embedded in Impregum (3M ESPE) and stored in a solution of tap water with thymol crystals. Sixteen primary molars from 7 children were used to compare the mineral density in sound and carious areas, and 13 primary molars from 11 children were used for the comparison between mineral density and time in situ.
  
  
  RESULTS
  A statistically significant difference (31%) was found between the mineral density in carious enamel and sound enamel (p = 0.0006). In addition, a significant relationship was observed between the mineral density of sound enamel and the time the teeth had been in situ (r = 0.698). We also found two teeth with radiolucencies in the dentin with the enamel clinically showing only a non-cavitated carious lesion in the enamel. No significant differences were found between the mean mineral density in sound enamel surfaces and unaffected areas in surfaces of molars with enamel caries (p = 0.4373).
  
  
  CONCLUSIONS
  Local and general differences in enamel mineralisation are presented. Post-eruptive maturation seems to be present not only in permanent teeth but also in primary molars. Carious enamel has significantly less mineral density than clinically sound enamel.
authors.affiliation: Department of Cariology, Endodontology and Pedodontology, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University Amsterdam, Amsterdam, The Netherlands.
authors.forename: M Ec
authors.initials: ME
authors.lastname: Elfrink
authors.affiliation: Dentist in different practices, The Netherlands. Former student at Academic Centre for Dentistry Amsterdam.
authors.forename: K
authors.initials: K
authors.lastname: Kalin
authors.affiliation: Department of Functional Anatomy, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University Amsterdam, MOVE Research Institute, Amsterdam, The Netherlands.
authors.forename: L J
authors.initials: LJ
authors.lastname: van Ruijven
authors.affiliation: Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University Amsterdam, Amsterdam, The Netherlands.
authors.forename: J M
authors.initials: JM
authors.lastname: ten Cate
authors.affiliation: Department of Cariology, Endodontology and Pedodontology, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University Amsterdam, Amsterdam, The Netherlands.
authors.forename: J S
authors.initials: JS
authors.lastname: Veerkamp
mesh_terms: D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D003731:Dental Caries / Q000378:metabolism; D003743:Dental Enamel / Q000737:chemistry*; D003804:Dentin / Q000737:chemistry; D006801:Humans; D008903:Minerals / Q000737:chemistry*; D008963:Molar / Q000737:chemistry*; D014094:Tooth, Deciduous / Q000737:chemistry*; D055114:X-Ray Microtomography / Q000379:methods*
chemical_list: D008903:Minerals