[Differential-diagnostic features of combined periapical lesions].

The paper describes specific correlation of the clinical and molecular pathogenic features in various types of combined periapical lesions. Endodontic apical lesions combined with periodontal disease are characterized by specific radiological signs, shifts in oral fluid physical and chemical properties, the disruption of nitrogen metabolism, increased iron concentration, collagen disruption and impaired concentration ratio of calcium and phosphorous. General depression of immunoglobulin synthesis and increased concentration of cortisol and estradiol in oral fluid are also typical features of combined periapical lesions.