Altered levels of inorganic elements and carbon in both dentin and enamel in primary teeth from patients with osteogenesis imperfecta

Osteogenesis imperfecta (OI) is an inherited disorder of collagen which might manifest in dentin. OI is due to a collagen mutation where glycine is substituted by larger amino acids disturbing collagen fibril coiling. The defect collagen might impair dentin mineralization. As OI is a collagen disturbance, a majority of publications has focused on the organic components of tissues. The inorganic elemental deviation pattern in OI type I is not very well understood, especially not in dental tissues. The aim of this study was to analyze the elemental content pattern in dentin and dental enamel for 12C, 23Na, 24Mg, 31P, 39K, 77CaCl and 88Sr , by means of Secondary Ion Mass Spectrometry (SIMS) in addition to X-Ray Micro Analysis (XRMA) of Ca, P, O and C. The relative importance of critical elements for the outcome OI was analyzed using rule induction analysis. The conclusion from this study is striking differences in element composition of dental tissues from OI patients. Alterations in hydroxyapatite constituents Ca, P and O, together with carbon, were found in dentin as well as in enamel. Findings included elevated levels of phosphorus, calcium and magnesium in DI dentin. Oxygen levels in DI dentin were lowered, and fluorine levels in the central parts of enamel were also lowered. In enamel, carbon and chlorine were elevated. Rule induction analysis revealed elevated tissue levels of carbon to be obligate for the outcome OI in both dentin and enamel. These changes probably reflect aberrations in matrix mineralization during early odontogenesis. Changes observed in enamel are probably due to indirect effects of imperfect mesenchymal ectodermal interactions during early tooth formation. .