An electron microprobe analysis of osteofluorosis in the rabbit

Spontaneously occurring alimentary osteofluorosis associated with proliferative gastroduodenopathy in rabbits

Growing rabbits from two rabbitries, fed with commercial concentrates and hay, developed painful thickenings of the extremities. Four rabbits from each farm were clinically examined and necropsied. All animals showed multiple moderate to severe osseous proliferations of extremities and mandibles and a mild to severe proliferative gastroduodenopathy. Histologically, periosteal and endosteal hyperostosis and a mild to severe proliferation of the gastric and duodenal mucosa were noted. Bone analyses revealed 12,700 and 15,000 microg fluoride per gram of bone ash in affected rabbits, compared with 550 microg fluoride in a control animal. A highly elevated fluoride content was found in concentrates. Vitamin A levels were moderately increased only in one concentrate, and copper levels were normal. Results indicate that alimentary fluoride intoxication caused prominent bony proliferations in the examined rabbits. Whether the proliferative gastroduodenopathy is related to the elevated fluoride intake or represents an incidentally occurring secondary disease remains to be determined.

The multielemental analysis of bone. A review

Numerous elements, especially metals, possess biological activity. But until now, they were of interest mainly as ingredients of foods. This caused the grouping in essential and nonessential elements, and characteristic changes of their concentrations in tissues and body fluids of man are often accompanied by pathologic alterations. The growing interest in environmental influences on human, animal, and plant health has focused our view on the toxicity of certain elements. Often it depends on concentration (1) or chemical form (e.g., Cr3+ is essential whereas Cr6+ is venomous) if an element is vital or poisonous.

Electron probe micro-analysis for subsurface demineralization and remineralization of dental enamel

A quantitative study of fluoride distribution profile changes in dental enamel was conducted by means of electron probe micro-analysis (EPMA). Fluoride-deposited hydroxyapatite powders were chosen as fluoride standards, and analytical conditions were optimized. The lower limit of detection for fluoride was estimated to be 270 ppm, with an accelerating voltage of 5 kV, a specimen current of 40 nA, and a counting time of 40 seconds. Fluoride profiles in fluoride-treated dental enamel, which exhibited intact surface layers and subsurface demineralization, were determined. The results were also compared with those of an acid-abrasion method, and reasonable consistency was found between these two methods, although the acid-abrasion procedure yielded a slightly lower fluoride content in the initial layers, followed by a higher content of fluoride in the deeper layers. The precision of fluoride profile data obtained from EPMA permits further studies to be conducted on the kinetics of subsurface demineralization and intact surface layer formation ("white spot" formation) which is observed during the acid challenge of dental enamel.