Background. In orthopedic dentistry, cases of electrochemical reactions in the mouth are known in the presence of prostheses made of metal alloys. The phenomena of galvanism reflect the hidden processes of corrosion of structural alloys in the oral fluid, which makes it necessary to analyze the content of chemical elements of prostheses both in clinical conditions in patients with implants and in experimental conditions. Aim: comparative analysis of the content in the oral fluid in the clinic and in the experiment of trace elements of prostheses on implants. Material and methods. National Research Technological University MISIS analyzed artificial saliva after prostheses were in contact with Grade 4 and Grade 5 implants for 3 months. Elements were determined by spectrometry: titanium, cobalt, chromium, aluminum, vanadium, molybdenum, tungsten, manganese, nickel, iron. In clinical conditions, in 32 patients with fixed dentures on implants, the same chemical elements were analyzed by an identical spectrometric method. Results. Under experimental conditions, trace elements were found in the container around one Grade 4 implant with a crown: titanium (0.4 g/l), cobalt (3.8 g/l), chromium (0.5 g/l), aluminum (2.6 g/l), vanadium (0.6 g/l), molybdenum (1.5 g/l), tungsten (3.0 g/l), manganese (0.9 g/l), nickel (0. 5 g/l), iron (0.6 g/l). The Grade 5 implant was characterized by a greater degree of diffusion of trace elements of aluminum, nickel, manganese into artificial saliva. Mass spectrometry of the oral fluid in patients with dental implants reveals a more significant amount of trace elements in comparison with experimental data. The difference in the concentration of microelements from the composition of prostheses in clinical conditions and in the experiment ranges from 0 to 128 times minimum. Conclusion. The experimental stay of prostheses on implants for 3 months in artificial saliva is accompanied by the diffusion of all microelements of prostheses and implants into the environment, especially cobalt, aluminum, and vanadium. In clinical conditions, in comparison with experimental conditions, a more significant diffusion of microelements of prostheses into saliva is observed according to the data of its spectrometric study.

BACKGROUND: Search for new effective means of preventing inflammatory complications in the state of peri-implant tissues is relevant; in particular, products from coniferous greens produced by the Solagift company (Tomsk) are of interest. The bioeffective cell juice of the Siberian fir, the 100% carbon dioxide extract of Siberian fir (water fraction), stands out among them. Fir cell juice is recommended for enhancing immunity, preventing inflammatory diseases of the upper respiratory tract, and treating several pathological conditions. Fir juice contains vitamin C, carotene, polyphenolic compounds, flavonoids, iron, magnesium, copper, manganese, zinc, and maltoliron chelate complex (a natural antioxidant). AIM: This microbiological study aimed to examine the sensitivity of periodontal pathogens to bioeffective cell juice of Siberian fir of various concentrations. MATERIAL AND METHODS: A number of periodontal pathogens were cultivated in the presence of bioeffective Siberian fir cell juice in the following proportions: 1:5, 1:10, and 1:15. Incubation for up to 3 days was conducted in a reverse-spinner RTS-1 bioreactor (BioSan, Latvia) with automatic analysis of the optical density (OD) of the culture at a wavelength () of 850 nm. OD was measured in McFarland units (mcf). The assessment of culture growth control was based on the analysis of the growth phases of periodontal pathogens: adaptive (lag phase), exponential (log phase), stationary, and withering away. The following clinical isolates of microorganisms were used: Streptococcus constellatus, Staphylococcus aureus, Fusobacterium nucleatum, and Aggregatibacter actinomycetemcomitans. RESULTS: The microbiological study of the sensitivity of periodontal pathogens (such as S. constellatus, S. aureus, F. nucleatum, and A. actinomycetemcomitans) to bioeffective cell juice of Siberian fir showed a growth slowdown of microorganisms in the presence of fir juice and inhibition of the growth of a culture of periodontal pathogens when co-cultivated with fir juice. A significant decrease in the OD of cultures of all studied periodontal pathogens was observed at a fir juice concentration of 1:10 and 1: 5. At these concentrations, there was no growth of S. aureus culture, and the degree of decrease in the average OD of other periodontal pathogens reached 27.1% (A. actinomycetemcomitans), 31.8% (F. nucleatum), and 33.6% (S. constellatus).

BACKGROUND: The functional duration of implant prostheses in the complete absence of teeth is insufficiently represented in the special literature. Hence, the experience of using such prostheses of various designs over 20 years is summarized. AIM: To analyze the effectiveness of implant prostheses in the complete absence of teeth in terms of peri-implant tissue status MATERIAL AND METHODS: This study examined 23 patients with fixed dentures on 4 implants after 5 years and 30 patients with fixed dentures on 6 implants after 10 years from the manufacture date. Overdentures on 4 implants with rigid attachments were analyzed in 24 patients after 10 years and with elastic attachments in 28 patients after 20 years. Additionally, 20 years ago, 73 patients received overdentures with bar fixation on 2 implants. The evaluation criteria include the detection of mucositis, peri-implantitis with 1/3 and 1/2 bone resorption, and implant removal. RESULTS: When summarizing the state of implants over 20 years, the following results were obtained: removable dentures are more effective with rigid attachments on a bar and 4 implants and less effective on 2 implants (47.9% and 65.2% of implant removals, respectively); fixed prostheses with complete absence of teeth (experience of 10 years of use) are preferred with support for 6 implants (28.3% of removals vs. 42.4% with support for 4 implants). CONCLUSIONS: In conclusion, the proportion of removed implants is 50% of the installed ones. The functional average period of fixed prostheses on 6 implants in the absence of teeth is 10 years (on 4 implants is 5 years) and removable prostheses on 24 implants with elastic and rigid attachments is 5 years.

ABSTRAKT Relevance. Currently, a large number of metal structures are used in dentistry: implants, inlays, pins, dentures, etc. These structures are often made of various metals and metal alloys with different electrochemical potentials. This circumstance can lead to the appearance of a galvanic couple in the mouth, i.e. galvanic cell, consisting of metal structures. In the available literature, there are no data on the frequency of detection of galvanic pairs of metal structures in the mouth, in the absence of galvanic syndrome and diseases of the oral mucosa. Target. The study of the frequency of detection of galvanic pairs of metal structures in the mouth, in the absence of galvanic syndrome and pathological changes in the oral mucosa. Materials and methods. A survey was conducted for the presence of galvanic pairs of metal structures in the mouth, 133 patients aged 33 to 87 years. In all patients, galvanic syndrome and pathological changes in the oral mucosa were absent. Depending on age, the patients were divided into 4 groups. The first group consisted of 33 young patients from 33 to 44 years old, the second - 35 middle-aged patients from 45 to 59 years old, the third - 35 elderly patients from 60 to 74 years old, the fourth - 30 elderly patients from 75 to 87 years old. The determination of the electrochemical potentials of metal structures in the mouth was carried out according to the method developed at the Department of Therapeutic Dentistry of the E. V. Borovsky Institute of Dentistry of the First Moscow State Medical University. THEM. Sechenov (Sechenov University). An electrode made of 999 gold was used as an active indicator electrode, which was used to touch metal structures in the mouth during the study. An EHP-1 silver chloride electrode was used as a passive reference electrode. A Fluke 115 multimeter was used as a measuring device during the study. Results. In the first group, which consisted of young people, galvanic pairs were found in 18% of the examined, while the number of metal structures in this group was 5.2 + 2.1. In the second group, in middle-aged persons, along with a tendency to increase the number of metal structures in the mouth, up to 7.4 + 3.5, the number of persons in whom galvanic vapors were found in the mouth increased, up to 23%. In the third group, in the elderly, galvanic vapors in the mouth were detected in the maximum number of examined, compared with other groups, which amounted to 26%. In this group, the maximum number of metal structures in the mouth was also observed in comparison with other groups of the examined. In this group, this indicator was 7.9 + 4.1. In elderly people (group 4), the number of patients with galvanic pairs of metal structures in the mouth decreased to 20%. This was due to the trend towards a decrease in the number of fixed metal structures, due to an increase in the number of removable dentures. The indicator of the presence of metal structures in the oral cavity in this group was 5.9 + 1.8. Conclusion. The frequency of detection of galvanic pairs of metal structures in the mouth is associated not so much with the age of the examined persons, but to a greater extent with the number of metal structures in the mouth. With an increase in the number of metal structures, the probability of the appearance of a galvanic pair in the mouth, formed by metal structures with different electrochemical potentials, increases. Key words: electrochemical potential, metal constructions, galvanic couples, galvanic cell.