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Intrafibrillar mineral may be absent in dentinogenesis imperfecta type II (DI-II)
J H Kinney1, J A Pople, C H Driessen
1Department of Preventive and Restorative Dental Sciences, University of California, San Francisco 94143-0758, USA. jkinney@itsa.ucsf.edu
Journal of Dental Research
|August 14, 2001
Summary
Dentinogenesis imperfecta type II (DI-II) teeth show significantly lower mineral content and altered apatite crystal structure compared to normal teeth. This study reveals a lack of intrafibrillar mineralization in DI-II dentin, impacting its structural integrity.
Area of Science:
- Biomineralization
- Materials Science
- Dental Research
Background:
- Dentinogenesis imperfecta type II (DI-II) is a genetic disorder affecting dentin formation.
- Understanding the mineral structure of DI-II dentin is crucial for explaining its pathological characteristics.
Purpose of the Study:
- To investigate the mineral concentration and crystallite structure in normal and DI-II dentin.
- To elucidate the mineralization process in DI-II using advanced imaging and scattering techniques.
Main Methods:
- High-resolution synchrotron radiation computed tomography (SRCT) for mineral concentration analysis.
- Small-angle X-ray scattering (SAXS) to determine apatite crystallite size, shape, and organization.
Main Results:
- DI-II dentin exhibited a 33% lower mineral concentration compared to normal dentin.
- Normal dentin showed intrafibrillar mineralization, evidenced by SAXS diffraction peaks, while DI-II dentin lacked these peaks.
- Crystallites in DI-II dentin were thicker and consistently needle-like, unlike the varied shapes in normal dentin.
Conclusions:
- DI-II dentin is characterized by reduced mineral content and a lack of intrafibrillar mineralization.
- The altered crystallite morphology and organization in DI-II dentin contribute to its abnormal structure.
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