This article presents results of the examination of patients with periodontal tissue pathology: a study of calcium-phosphorus metabolism and bone mineral density. The aim of the study was to determine the state of calcium-phosphorus metabolism and bone mineral density in patients with periodontal tissues diseases. The analysis of the obtained results shows that in patients with generalized periodontitis the course of the disease is accompanied by an imbalance in the parameters of bone metabolism. Densitometric studies showed the presence of various disorders of the structural and functional state of skeletal bone tissue (norm/osteopenia I-II-III degree/osteoporosis) and bone metabolism in patients with generalized periodontitis.