The investigation of mixed saliva protein structure of persons with healthy oral and dental tissues before and after detailed cleaning of teeth from dental plaque. Electrophoretic examination of liophylised saliva of children aged 13-15 years was done on polyacrylamide gel SDS. The comparison was performed compared to the normal human serum in pulled sample. Obtained results revealed that electrophoresograms of persons with healthy periodontal and dental tissues were the same as electrophoresograms of persons with periodontal disease and caries. Electrophoresogram was improved after the detailed teeth cleaning and plaque removal and was similar to the sample of persons with healthy periodontal and dental tissues. Electrophoresograms before and after dental treatment were used for the comparison. The alterations of protein structure of mixed saliva showed that the tendency of establishing the dynamic balance in relation to adjacent tissues existed inspite of continual secretion.