The article gives a detailed analysis of oral cavity microbiocenosis features of 36 patients with type II diabetes for 5 years. These data reflects microbiocenosis features before and after orthopedic treatment with metal-ceramic and pressed crowns. These results indicate that frequency of occurrence and the number of microorganisms of the genus Streptococcus, Staphylococcus (including S. aureus), Peptostreptococcus and Candida is significantly higher in patients after orthopedic treatment with pressed crowns than with metal-ceramic crowns. A high percentage of normal microflora, particularly lactobacilli (60%), was revealed on gingival mucosa in patients after orthopedic treatment with metal-ceramic crowns.