A study was carried on 69 patients. Experimental group (N=50) received new upper mobile dentures (acrylic or wironit), while the control group (N=19) did not have dentures. Groups were of similar age.

An anamnesis was taken, followed by a thorough clinical examination of the oral cavity and microbiological tests investigating effects of various denture base materials on oral tissues. Clinical tests assessed the degree of palatal inflammation under the denture, amount of saliva, oral hygiene, periodontal and teeth status. Microbiological tests examined palatal and denture swabs for candida and bacterial species (including mutans streptococci and lactobacilli counts from samples of saliva). Results have shown that after denture settlement in the mouth, palatal inflammation took place in 56% patients in experimental group. The experimental group showed also significant increase in plaque and gingival indices, as well as higher average number of teeth affected with caries and periodontal disease. The palatitis prothetica was associated with significantly greater colonization of palate and dentures with Gram –negative cocci, Gram- positive rods and C. albicans. Gingival and plaque indices were correlated with caries and periodontal diseases, S. mutans and lactobacilli counts were not. Different denture base material did not have an effect on the degree of palatal inflammation, gingival and plaque indices, and averige periodontal affected teeth, but wironit wearers had lower number of caries affected teeth. Patients with acrylic dentures (total and partial) experienced more discomfort and had poorer retention than patients with wironit dentures.

Results did not support one best denture base material, but indicated that dentures create colonization of various species of oral pathogens that is based on local factors (primarily oral and denture hygiene).