title: Cross-sectional hardness of enamel from human teeth at different posteruptive ages.
abstract: This study evaluated, by cross-sectional hardness (CSH), enamel maturation at different depths in sound human teeth at different posteruptive ages (12 per age group): unerupted (molars; control), 2-3 years (premolars), 4-10 years (premolars) and >10 years (molars). Cross-sectional Knoop hardness was measured at 10, 30, 50, 70, 90, 110, 220 and 330 mm depth from the surface. The data were subjected to two-way ANOVA followed by Bonferroni's pairwise tests (a = 0.05). The CSH significantly increased with posteruptive age, indicating that the time of exposure in the oral cavity might result in deep enamel maturation.
authors.affiliation: Department of Pediatric Dentistry, Orthodontics and Public Health, Bauru School of Dentistry, University of São Paulo, Bauru, Brazil.
authors.forename: C A B
authors.initials: CA
authors.lastname: Cardoso
authors.forename: A C
authors.initials: AC
authors.lastname: Magalhães
authors.forename: D
authors.initials: D
authors.lastname: Rios
authors.forename: J E O
authors.initials: JE
authors.lastname: Lima
mesh_terms: D000367:Age Factors; D019412:Anatomy, Cross-Sectional; D001641:Bicuspid / Q000033:anatomy & histology; D002648:Child; D002675:Child, Preschool; D003743:Dental Enamel / Q000033:anatomy & histology* / Q000254:growth & development; D006244:Hardness; D006801:Humans; D008963:Molar / Q000033:anatomy & histology; D010865:Pilot Projects; D014078:Tooth Eruption / Q000502:physiology*; D014097:Tooth, Unerupted / Q000033:anatomy & histology