To test the hypothesis that enamel biomineralization is regulated by sequential expression of an intrinsic genetic program, we designed experiments to determine if a serumless, chemically-defined medium is permissive for position-dependent ameloblast differentiation and subsequent enamel tissue-specific biomineralization in vitro. In the absence of serum or other exogenous growth factors, Swiss Webster strain mouse embryonic (15-and 16-days gestation) mandibular first molar tooth organs (cap stage) developed within 21 days in vitro into well-defined molar tooth organs expressing dentine and enamel biomineralization. Analysis of data obtained from von Kossa histochemistry for calcium salt formation, as well as ultrastructural information obtained from x-ray microanalysis, electron diffraction, transmission electron microscopy and scanning electron microscopy documented tissue-specific patterns of calcium hydroxyapatite formation in the absence of scrum within organotypic cultures in vitro. An as yet unknown intrinsic genetic program regulates enamel formation in vitro.
Bringas, P. Jr.; Nakamura, M.; Nakamura, E.; Evans, J.; and Slavkin, H. C.
"Ultrastructural Analysis of Enamel Formation During in vitro Development Using Chemically-Defined Medium,"
Scanning Microscopy: Vol. 1
, Article 25.
Available at: https://digitalcommons.usu.edu/microscopy/vol1/iss3/25