The purpose of our research was studying changes of endogenic intoxication after treatment of the exacerbation of chronic periodontitis in patients with accompanying pathology — chronic pyelonephritis. The accompanying pathology worsened the course and results of treatment of periodontitis that proved to be true high level of midmolecular olygopeptides in the blood during the different periods of the disease: (0.522±0.018) and (0.362±0.018) agreed units (Р<0,05) accordingly before and after treatment of periodontitis.
