Intrafibrillar mineral may be absent in dentinogenesis imperfecta type II (DI-II).

Abstract

High-resolution synchrotron radiation computed tomography (SRCT) and small-angle x-ray scattering (SAXS) were performed on normal and dentinogenesis imperfecta type II (DI-II) teeth. The SRCT showed that the mineral concentration was 33% lower on average in the DI-II dentin with respect to normal dentin. The SAXS spectra from normal dentin exhibited low-angle diffraction peaks at harmonics of 67.6 nm, consistent with nucleation and growth of the apatite phase within gaps in the collagen fibrils (intrafibrillar mineralization). In contrast, the low-angle peaks were almost non-existent in the DI-II dentin. Crystallite thickness was independent of location in both DI-II and normal dentin, although the crystallites were significantly thicker in DI-II dentin (6.8 nm [SD = 0.5] vs. 5.1 nm [SD = 0.6]). The shape factor of the crystallites, as determined by SAXS, showed a continuous progression in normal dentin from roughly one-dimensional (needle-like) near the pulp to two-dimensional (plate-like) near the dentin-enamel junction. The crystallites in DI-II dentin, on the other hand, remained needle-like throughout. The above observations are consistent with an absence of intrafibrillar mineral in DI-II dentin.

• Authors: J H Kinney, J A Pople, C H Driessen, T M Breunig, G W Marshall, S J Marshall
• Journal: Journal of dental research (J Dent Res) Vol. 80 Issue 6 Pg. 1555-9 (Jun 2001) ISSN: 0022-0345 [Print] United States
• PMID: 11499512 (Publication Type: Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Collagen

Topics

• Adolescent
• Adult
• Collagen (chemistry)
• Crystallization
• Dentin (diagnostic imaging, pathology)
• Dentinogenesis Imperfecta (diagnostic imaging, pathology)
• Female
• Humans
• Imaging, Three-Dimensional (methods)
• Molar, Third (pathology)
• Scattering, Radiation
• Synchrotrons
• Tomography, X-Ray Computed (methods)