Comparison of the effect of sodium fluoride and calcidiol on the rib cortical-endosteal surface remodeling in dogs receiving prednisone.

The effects of sodium fluoride and calcidiol on the remodeling of the rib cortical-endosteal surface were compared in dogs treated with prednisone over long-term periods. In the study histomorphometric and tetracycline-labeling methods were used. It was found that administration of sodium fluoride in combination with calcidiol and calcium carbonate limited the development of prednisone-induced osteoporosis to a higher degree than treatment with calcidiol and calcium. This included less enhancement of the bone resorption surface, an increase in both the bone formation surface and osteoid seam thickness in conjunction with a lower reduction in the mineralization rate. The changes induced by sodium fluoride had a favorable effect on the ratio of the resorption to the formation processes at the basal multicellular units of bone turnover.