THE MICROFLORA ADJACENT TO OSSEOINTEGRATED IMPLANTS SUPPORTING MAXILLARY REMOVABLE PROSTHESES

The study examines the effect of maxillary prosthetic appliances on the composition of the microflora in the peri-implant sulcus. Two groups of patients participated. One group consisted of 18 people with removable prostheses, and a second group of 9 people with fixed prostheses was chosen to match them in age, sex and function period of their prosthetic appliances. One implant site per patient was chosen for microbiological sampling, and the samples were taken on 2 separate occasions from all the subjects, with a 3-month interval. From those with removable prostheses, a further sample was collected by scraping a squared area from the mucosal side of the prosthesis. The prevalence of black-pigmented Porphyromonas/Prevotella, Actinobacllus actinomycetemcomitans, mutans streptococci, lactobacilli, enteric bacteria and yeasts was analysed using blood-agar and selective agar media. The results show that the prevalence was significantly higher for Lactobacillus, Prevotella spp. and yeasts in subjects with removable prostheses than in subjects with fixed prostheses. No significant difference was registered in the pattern of microbial composition in subjects with the removable prosthesis when the peri-implant sulcus plaque and the biofilm on the corresponding mucosal side of their prosthesis were examined. The insertion of a removable reconstruction to cover the area of the osseointegrated implants gave rise to a progressive change in the peri-implant plaque towards a more aciduric microflora.