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Title: Intrafibrillar Mineral May be Absent in Dentinogenesis Imperfecta Type II (DI-II)

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. Three normal and three DI-II human third molars were used in this study. The normal molars were unerupted and had intact enamel; donors were female and ranged in age from 18-21y. The DI-II specimens, which were also unerupted with intact enamel, came from a single female donor age 20y. 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 nonexistent 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 (s.d. = 0.5) vs 5.1 nm (s.d. = 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. Themore » 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.« less
Authors:
Publication Date:
OSTI Identifier:
784895
Report Number(s):
SLAC-PUB-8790
TRN: AH200131%%607
DOE Contract Number:
AC03-76SF00515
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: 29 Mar 2001
Research Org:
Stanford Linear Accelerator Center, Menlo Park, CA (US)
Sponsoring Org:
USDOE Office of Energy Research (ER) (US)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 59 BASIC BIOLOGICAL SCIENCES; APATITES; COLLAGEN; COMPUTERIZED TOMOGRAPHY; DENTIN; X-RAY DIFFRACTION; MINERALIZATION; NUCLEATION; SMALL ANGLE SCATTERING; TEETH; CRYSTAL STRUCTURE