The microelement composition of saliva makes it possible to analyze the processes occurring in the oral cavity and the body as a whole, both under conditions of normal functioning and in the presence of pathological processes. At the same time, the technical simplicity of performing trace element analysis of salivary fluid as a possible diagnostic criterion for various diseases contributes to a significant number of studies devoted to the search for possible correlations between the trace element composition of salivary fluid and various types of pathologies. The possibility of using the analysis of the microelement composition of saliva in determining concomitant pathologies of organs and systems of the body as a whole is a promising direction in scientific research, including applied research. The article analyzes the possibilities of using microelement analysis of saliva in such pathologies as psoriasis, Parkinson's disease, schizophrenia, pathology of the gastrointestinal tract, diabetes mellitus, pathology of the cardiovascular system, giardiasis, oncological diseases. It is noted that at present, the determination of the microelement composition of saliva in various pathological conditions is considered as a promising clinical direction that allows for the simultaneous diagnosis of several diseases in real time.

Background:chronic apical periodontitis is a common pathology in dentistry, especially in endodontics. It is necessary to systematize data concerning commonly used irrigation solutions. The development of new protocols for endodontic treatment is a very promising direction. The use of a polyhexanide-based antiseptic can positively affect the results of endodontic treatment. Methods: the review was carried out involving the search for English language research and meta-analyses in the Google Scholar and PubMed databases. Results: the number of literary sources that were identified during the literature review is 180. After excluding publications that did not match the search criteria, the total number of articles included in the systematic review was determined to be 68. Conclusions: polyhexanide is a promising solution for infected root canal irrigation. The antibacterial activity of this substance is suitable for the elimination of pathogens responsible for the appearance of apical periodontitis.

The comorbidity of diseases reflects the mutual influence of pathological conditions of individual organs and systems of the body, which requires taking into account the current state of the patient. The presence of comorbidity in modern dentistry is one of the important problems that require attention in diagnosing a patient's condition, selecting treatment tactics and predicting the results of interventions. The possibility of diagnosing concomitant diseases by changing the microelement composition of saliva makes it possible to more effectively determine their presence, the severity of the existing concomitant pathology and determine the optimal treatment tactics.Trace elements contained in saliva regulate a number of biological processes, and their level reflects the state of homeostasis of the oral cavity, and in systemic diseases, the composition of saliva has a strong correlation with blood plasma and, therefore, can reflect the state of health of the body.There are both comorbidity of exclusively dental pathology, and comorbidity of dental diseases with other somatic pathologies. At the same time, the determination of changes in the microelement composition of saliva may indicate the development of inflammatory processes both in the oral cavity and in the body as a whole, a decrease in antioxidant protection, damage to enzyme systems and ion channels, pathological changes in mucous membranes, etc. . The possibility of analyzing the microelement composition of saliva in assessing the comorbidity of a patient's comorbidities seems to be a promising area of research in modern dentistry.