Chewing is an important function ensuring the proper nutrition of the patient. The condition of the oral cavity, including the presence of the patient's own teeth and reconstruction of teeth gaps, significantly determine the quantity and quality of food consumed. Malnutrition may be an obvious consequence of improper diet, caused by the lack of effective chewing function, but there is also taken into account the influence of this aspect on the development of obesity. Disease for which the type of diet is postulated as its potential risk factor is gastritis caused by Helicobacter pylori infection. Tooth loss is linked to a higher incidence of diseases such as cancer of the esophagus and stomach. Currently, the main reason for such a correlation is the influence of changes in the oral cavity bacterial flora, which occurs in patients who lose their own teeth, on the stimulation of the carcinogenesis process. On the other hand, prosthetic rehabilitation with the use of full and partial settling dentures, aimed at restoring the chewing function, may carry the risk of developing systemic diseases caused by local Candida albicans infection. In the light of the hypotheses presented above, it is important to determine the impact of the lack of dentition and its restoration with the use of removable prosthetic restorations on the indicators of the diseases in question.