Male rats, 21‐100 days old at the start of different experiments, were kept for several weeks on synthetic diets, either adequate, or deficient in calcium (Ca) and at the same time low in protein and high in sucrose.
For varying parts of the experimental periods the rats were given either dist. water, or water supplied with 2000 ppm Ca, 40 ppm fluoride (F), or both in a compatible form.
Assessment was made of several parameters of the femoral bone density and of two histometric parameters of the alveolar bone density.
The bone density in animals on Ca‐deficient diet was greatly improved by supplying either Ca or Ca+F with the drinking water. There was a tendency to higher mineral density with Ca+F supply than with Ca alone. Rats that had been on a high F, adequate diet were much more resistant to bone mineral depletion by a subsequent Ca‐deficient diet than were control rats that had been on the same diet without F.
The alveolar bone generally reacted more strongly than the femoral bone to both deprivation and supplementation, and the tissue between the roots of one molar (M 2) more than the tissue between two molars (M 1–2).
The correlations of alveolar bone parameters to femoral weight, ash, Ca and P content were all positive, in most cases statistically significant, and generally stronger for the M 2 than for the M 1–2 tissue. In an experiment where the deficient diet was supplied either as powder or as bread the results seemed to support the concept of an influence of masticatory force, particularly on the interdental bone septa.
The connection between generalized osteopenia and alveolar bone loss and the roles of Ca and F are discussed.