Scanning electron microscopic observations of fibrous structure of cemento-dentinal junction in healthy teeth.

Introduction: The cemento‑dentinal junction (CDJ) is a structural and biologic link between cementum and dentin present in the roots of teeth. Conflicting reports about the origin, structure and composition of this layer are present in literature. The width of this junctional tissue is reported to be about 2‑4 µm with adhesion of cementum and dentin by proteoglycans and by collagen fiber intermingling. Aim and Objective: The objective of this study is to observe and report the fibrous architecture of the CDJ of healthy tooth roots. Materials and Methods: A total of 15 healthy teeth samples were collected, sectioned into halves, demineralized in 5% ethylenediaminetetraacetic acid, processed using NaOH maceration technique and observed under a scanning electron microscope. Results: The CDJ appeared to be a fibril poor groove with a width of 2-4 μm. Few areas of collagen fiber intermingling could be appreciated. A detailed observation of these tissues has been presented.

Lead in teeth of a sample population of Baghdad

Teeth from 245 randomly selected inhabitans of Baghdad, all without any known exposure to lead, were analysed for lead content. In the City of Baghdad the geometric mean level of lead was 34.119 ppm in permanent teeth and 32.139 ppm in deciduous teeth; in a rural area the levels were 32.809 ppm and 23.442 ppm respectively. There were significant differences in the lead content of deciduous teeth derived from children living in different areas, but no such differences in permanent teeth. It is concluded that, in so far as tooth-lead reflects urbanization, this effect is demonstrated much more readily in deciduous teeth than in permaner teeth