THE USE OF MOLECULAR AND BIOCHEMICAL MARKERS OF BONE METABOLISM FOR SCREENING OF DENTAL HEALTH OF THE POPULATION
Authors: Sydorenko O.O. , Pavlov S.V. , Voznyi O.V. 
Published: June 2020

At present, the research interests of both dentists and clinical laboratory diagnosticians lie in the field of using oral fluid as an object of diagnostic estimation of molecular and biochemical markers in oral cavity diseases. It is commonly known that oral fluid has both organic and non-organic components. Non-organic components of saliva are represented by macro- and microelements that can be parts of various compounds or stay in the ionized form. Organic components are represented by proteins, carbohydrates, lipids, essential nitrogenous compounds (urea and uric acid), vitamins, hormones, organic and nucleic acids.

Compared with the traditional method of blood testing, the identification of markers in the oral fluid has several advantages. They are non-invasiveness, atraumatic character for the patient, the absence of stress typical of venipuncture; simpler conditions of storage and transportation due to the liquid state (unlike whole blood, which tends to coagulate); being able to take biological material an unlimited number of times; no need for qualified personnel and special equipment when taking oral fluid.

The introduction of biological markers into the complex of dental checkups is one of the topical tasks of modern dentistry and clinical laboratory diagnostics. This is particularly important for those dental patients whose living or working conditions are accompanied by harmful chemical factors.

The authors have performed complex research of lactoferrin, cathelicidin, and MMP8 present in the oral fluid of 50 patients who worked under harmful conditions (group 1), and of other 50 patients whose work is not associated with the harmful influence of chemical factors (group 2). The oral fluid was collected on an empty stomach in the morning by spitting into a sterile glass tube. The biomass was centrifuged and stored at 300C, and the amount of lactoferrin (Hycto Biotech, the Netherlands), cathelicidin (Hycult Biotech, the Netherlands), and MMP8 (Matrix Metalloproteinase-8) was determined in the test samples. The analysis was performed by enzyme-linked immunosorbent assay based on the use of a "sandwich" variant of solid-phase enzyme-linked immunosorbent assay. The procedure was performed on the enzyme-linked immunosorbent assay ImmunoChem-2100 (USA). The analysis was performed in 96-well microplates, the bottom of the wells was covered with monoclonal antibodies to the corresponding molecular marker.

The analysis of the oral cavity condition in patients of both groups demonstrated the presence of caries (100 % of group 1 patients, 80% of group 2 patients) and partial adentia (75% of group 1 patients, 60% of group 2 patients). Secondary to the above-mentioned abnormalities, group 1 and 2 patients had periodontal diseases. Such abnormalities were registered in 87% of group 1 patients; in group 2 patients, such changes were less explicit and were present in 67% of the patients. On the contrary, it was established that the patients of both groups presented with a statistically significant increase of lactoferrin in the oral fluid (on average, 81% and 40% higher, respectively, in groups 1 and 2) and MMP8 (64% and 24% higher), as well as a decrease in cathelicidin concentration (87% and 42% lower) in comparison with the patients of group 3.

The established pathological biochemical changes indicate pathological processes in the oral cavities of the research groups of patients.

In modern practice, Lf is used as an organ-specific marker of the activation of a pathological process to diagnose and predict the course of mucosal and periodontal diseases. At the same time, the decrease in oral cathelicidin LL37 reflects the suppression of local immunity in the oral cavity and is regarded as a pathogenic chain in the progression of diseases of the mucosa, periodontium, including dental caries in patients. Similar dynamics of cathelicidin in group 1 patients, in our opinion, explains the intensity of oral disease development in this category of patients. Thus, neutrophils and macrophages die under the action of aggressive chemical factors, as a result of which the pool of antimicrobial peptides, including cathelicidin, decreases.

The present markers determine the topicality and great potential of further research of the given molecular markers for both fundamental investigations and understanding the pathogenesis of oral cavity diseases in this category of patients. Besides, these indices can be used as independent markers for diagnosis, screening, and effective treatment of oral cavity diseases.