IMMUNOHISTOPATHOLOGICAL CHANGES OF BONE TISSUE DURING CHRONIC GENERALIZED PERIODONTITIS Article Sirak S.V., Shchetinin E.V., Garunov M.M., Grigoryants L.A., Andreev A.A., Petrosyan G.G., Dzgoeva M.G. Medical News of North Caucasus. Stavropol State Medical University. Vol. 14. 2019. P. 532-535