Background. At doing of the demountable prosthesis the most widespread basic material are acrylic plastics which lacks are the possibility of the microbe growth and the incomplete polymerization leading to the residual maintenance of the monomer in the prosthesis. Methods. On the basis of the clinical analysis and gums’ biopsies at 63 patients of 60-74 years old the parameters of the local immune homeostasis depending on a kind of a basic material of the demountable plate prosthesis - acrylic plastics Meliodent (Germany), Ftorax (Ukraine) and Basis (Japan) were investigated. Results. All examined patients had gingivitis and parodontitis of mild and moderate severity level. The analysis of the biopsies has shown considerable changes of structure of cellular cooperation of a mucous membrane in comparison with the control in all follow-up terms. These changes were accompanied by the increase in proliferative epithelium activity. More expressed reaction is registered on the prosthesis made of plastic of firm Ftorax. Direct strong correlation between the quantity of Langerhans cells and iodine value Svrakova is revealed at use of the acrylic plastic Ftorax and direct weak correlation - at use of the acrylic plastics of firms Meliodent and Basis. Conclusions. Expressiveness of inflammatory process in the mouth mucous membrane is caused by the changes of a quantitative parity of the elements supporting the immune homeostasis. Clinical and morphological changes of an orthopedic bed have appeared more expressed at using of the prosthesis made of plastic Ftorax that allows to recommend the plastics of other manufacturers as basic materials.