INTRODUCTION. Nickel-titanium alloys and cutting-edge design of endodontic files continue to revolutionize. In addition to variations in the design of nickel-titanium files, manufacturers have implemented several proprietary manufacturing processing procedures to improve their mechanical properties.
AIM. The aim of the study was to improve the quality of mechanical instrumentation of highly curved root canals based on the data of laboratory and experimental analysis of rotary endodontic instruments made of nickel-titanium alloys of various modifications.
MATERIAL AND METHODS. As part of the research, the following endodontic rotary files systems were studied during instrumentation of curved root canals: group 1 – Mtwo (VDW); group 2 – Race Evo (FKG), group 3 – Ultrataper next (Eurofile). A metallographic analysis of the instruments was performed, a morphological structure of the root dentin after instrumental was examined by scanning electron microscopy, as well as the amount of extruded debris was studied.
RESULTS. Groups 2 and 3 showed significant deterioration after three applications. Mtwo files showed a statistically higher amount of surface damage after five uses (p < 0.05). The smallest amount of extruded debris was found in the group 2, while the largest number of root dentin irregulations was found in the groups 1 and 3 (p < 0.001).
CONCLUSIONS. A different degree of the surface damage of the instruments was revealed, depending on the number of treated root canals. The safest and most effective endodontic system for the mechanical preparation of curved root canals is the Race EVO.

AIM. To evaluate the effectiveness of using the material Sealpex with gutta-percha pins using the lateral condensation method for permanent obturation of the root canals of teeth with periapical pathology and pathologically destroyed apical constriction.
MATERIAL AND METHODS. The root canals of 94 teeth with destructive forms of periodontitis were filled with Sealpex. Depending on the degree of apical constriction, patients were divided into three groups. Follow-up of patients was carried out for 4 years.
RESULTS. Using SEM, in 80% of cases, single micro cracks were detected between the dentin of the root canal wall and the sealer. In the area of wide apical openings, the fit of the material is loose, and it is removed beyond the root apex. The material diffuses into the root dentin. Statistical studies have shown a high percentage of successful treatment of destructive forms of periodontitis with the use of Sealpex.
CONCLUSIONS. Endo-sealant extended beyond the apex of the root canal does not mean dense obturation of the apical foramen. The presence of micropores and microcracks in the endosealant can be regarded as evidence of poor sealing of the channel. The use of Sealpex is especially effective when filling teeth of groups, I and II with destructive forms of periodontitis

INTRODUCTION. Tooth decay and its complications are prevalent dental issues among adults. Endodontic treatment is the standard of care for complicated caries, specifically pulpitis and periodontitis. Endodontic irrigants, which are placed in the root canal lumen for a specific duration, can affect the intracanal dentin structure (organic and inorganic substances) in various ways. The use of polyhexanide-based antiseptic products in endodontics is a promising idea to overcome microbial resistance and minimize microbial-related endodontic treatment failures.
AIM. The aim of this study is to investigate the qualitative impact of standard irrigation solutions and a polyhexanide-based composition on the collagen matrix of dentin.
MATERIALS AND METHODS. The study investigated the effect of nine solutions on the dentin of the tooth root. Twelve intact maxillary third molars extracted for orthodontic reasons were taken for the study. The teeth were fixed in a 10% neutral formalin solution for at least one day and were decalcinated. 5–10 μm thick sample sections were made and stained with picrosirius (Picrosirius Red, Biovitrum, Russia) before being examined under polarized light. The histological slice was analyzed using a Carl Zeiss (Germany) software and hardware complex based on ZEN v3.0 and light microscope Axioimager M.1. All microphotos were loaded into the Fiji distribution program of ImageJ for microscopy pixel classification.
RESULTS. Upon analysis of the diagrams, it appears that there is a lower amount and density of stained dentin collagen array after exposure to sodium hypochlorite solutions of 3% and 1.5%, as well as polyhexanide.
CONCLUSIONS. The data obtained from the histogram analyzer of samples stained with picrosirius suggests that polyhexanide may have a qualitative effect on the organic structure of hard tissues, particularly collagen.

AIM. To analyze the stability of the results of aesthetic and functional restoration of frontal teeth in young people with preserved systemic and dental health based on expert assessments and subjective conclusions of the patient.
MATERIALS AND METHODS. The quality preservation of 63 composite restorations of frontal teeth performed a year ago in 54 patients aged 19–27 years with preserved systemic and dental health was analyzed by experts using the Ryge international assessment system. The calculation of integral and scale indicators of the dental index “Oral Health Impact Profile” OHIP-14-aesthetic-RU supplemented the selfassessment of the quality of previously performed dental restoration treatment in the smile area.
RESULTS. In 12 months after the restoration treatment most composite restorations corresponded to high aesthetic and functional characteristics in terms of the quality of preservation of the restored anatomical shape (respectively 70.0–61.5%), texture and color of the surface (66.7–65.4%) and edge fit (66.7–65.4%). The largest number of unacceptable assessments of the quality of restoration of III-IV classes were obtained according to the criteria of “Edge fit” (6.7% and 15.4%, respectively) and “Surface quality” (6.7%). The absolute majority (96.4%) of patients are satisfied with the quality of previously performed restoration and their preservation, which was confirmed by both professional opinions of dental experts and indicators of the aesthetically oriented dental quality of life index OHIP-14-aesthetic RU (the integral indicator was 5.92 ± 1.31 points), comparable with the index values in healthy young people with an intact dentition.
CONCLUSIONS. The use of modern light-curing composite materials for the treatment of carious defects of anterior teeth makes it possible to achieve high aesthetic and functional results of restoration according to its comprehensive (objective / subjective) assessment in the long-term follow-up.

AIM. To identify the ability of an ex tempore paste with metronidazole, chlorhexidine and chloramphenicol, to disinfect root canals in patients diagnosed with “Chronic apical periodontitis” K04.5.
MATERIALS AND METHODS. The study involved 30 patients, 61 root canals diagnosed with “Chronic apical periodontitis” K04.5. Treatment was carried out in accordance with clinical recommendations (treatment protocols) for the diagnosis: “Diseases of periapical tissues”, approved by Resolution No. 18 of the Council of the Association of Public Associations “Dental Association of Russia” dated September 30, 2014, updated on August 2, 2018. Biological material from the contents of the root canal was taken before and after the introduction of a paste with metronidazole, chlorhexidine and chloramphenicol into the root canal for 5 days. The following methods were used: clinical, microbiological. The total microbial number, gram-positive and gram-negative microorganisms, fungi were determined. A polymerase chain reaction (PCR) was carried out. Statistical analysis of the data included a description of accounting characteristics and assessment of the statistical significance of changes in the studied indicators. p < 0.05 was selected as the critical level of statistical significance of differences (p).
RESULTS. Statistical analysis showed a pronounced, statistically significant negative dynamics for all microbiological indicators in the structure of the root canal biofilm.
CONCLUSIONS. The data obtained allow us to conclude that an ex tempore paste with metronidazole, chlorhexidine and chloramphenicol can be used in the treatment of patients diagnosed with “Chronic apical periodontitis” K04.5 as an intracanal drug. It reduces all sown cultures of microorganisms in a short time (5 days).

AIM. To conduct a systematic review to evaluate the differences between the clinical performance of restorations made with total-etch and self-etch techniques.
MATERIALS AND METHODS. A literature search was conducted in the Pubmed, Google Scholar and Cyberleninka databases. The research was done according to the PICO strategy. Articles from the last 10 years (2013–2023) were included in the review.
RESULTS. After screening 1005 articles, 52 studies were subjected to data extraction. There were no statistically significant differences in any study regarding recurrence of caries. In 9 of 14 articles, retention was higher with the total-etch technique. Total-etch groups showed better marginal adaptation in 11 of 19 studies. 11 of 17 studies recorded the least marginal staining using the total-etch technique. None of the studies found statistically significant results for the presence of post-operative sensitivity at the end of the follow-up period. However, three studies reported statistically significant evidence of post-operative sensitivity at baseline, and after 12 months (1/2 follow-up) in the total-etch groups only.
CONCLUSIONS. Both methods show effective and clinically acceptable restoration performance.

AIM. To conduct a literature review and establish the relationship between gender stereotypes and dental health saving among students and to conduct our own analysis among higher education institutions such as: RUDN, RNIMU, MIREA.
MATERIALS AND METHODS. A systematic literature review in the electronic databases of Google Scholar and Pubmed was conducted. Articles with content based on identifying the role of gender on oral health among 18–25-year-olds were reviewed. Sixty articles were reviewed, of which 10 from Pubmed and 50 from Google Scholar were selected. After selecting articles according to criteria, the total number of studies was 30. In addition, we conducted our own analysis among universities such as: RUDN, MIREA, RNIMU. 66 people (48 girls and 18 men) participated in the survey.
RESULTS. We established the relationship between gender stereotypes and saving dental health, but we do not exclude that the level of oral health among students is individual and depends only partly on gender.
CONCLUSION. It is possible to note the influence of gender stereotypes regarding saving dental health. Girls are more careful about the state of oral cavity and health in general. This conclusion is based on the increased frequency of visits to the dentist for preventive examinations. The male part of the population, due to lack of knowledge in the field of prevention, improperly care for their oral cavity, this is expressed in the wrong brush, its coarser use and lack of instructions for daily brushing. The attitude of men towards the dentist plays an important role. Due to lack of habit and less awareness of health issues, they are more likely to be exposed to discomfort and stress during the appointment than girls. In conclusion, we would like to say that gender stereotypes have a place, but still the level of dental health among students is individualized and only partly depends on gender.

INTRODUCTION. The pathogenetic relationship between periodontal and pulp diseases was first described by Simring and Goldberg in 1964. Since then, the term “endodontic-periodontal” lesion (or “endo-perio”) has been used to describe lesions caused by inflammatory products found to varying degrees in both the periodontal and dental pulp tissues. The pulp and periodontium have embryonic, anatomical and functional relationships. The simultaneous presence of changes in pulp tissue and inflammatory periodontal diseases can complicate diagnosis and treatment planning. The etiology, pathogenesis and treatment methods of endodontic-periodontal lesions can vary from quite simple to relatively complex aspects. Knowledge of the basis of concomitant inflammatory processes in the pulp and periodontium is important for making the correct diagnosis.
AIM. Carry out a systematic analysis of the literature and summarize the available data on etiopatogenetic relations, diagnostic features and clinical history of endodontic periodontal dental lesions. MATERIAL AND METHODS. A systematic literature analysis was carried out, as well as a manual search in the databases PubMed, Google Search, eLibrary, disserCat, Cyberleninka. Among national and foreign publications corresponding to the topic of this review, 28 publications were selected for systematic analysis, the results of literature review are presented in this article.
CONCLUSION. This systematic review found that dental anatomy and the etiology of endodontic periodontal lesions are the basis for difficulties in the diagnosis and treatment of patients with endo-periodontal lesions. Determining the prevalence of infection and the individual characteristics of EPP pathogenesis in patients in this group remains a challenge. In the future, it is necessary to develop new methods of diagnosis, prophylaxis and complex treatment of combined periodontal tissue and tooth pulp, which will improve the prognosis of treatment of injured teeth in the long term.

While using a clinical case as an example, in this article we described the usage of an expanding appliance based on palatal orthodontic mini-implants for the upper jaw.

INTRODUCTION. The relevance of the study is related to the increased uncontrolled consumption of chewing gum by children.
AIM. The aim is to study the functional state of masticatory muscles in patients with changeable dentition using chewing gum in different modes.
MATERIALS AND METHODS. The study was carried out on 31 children, the average age of whom was 8.5 ± 1.2 years. It is at this age there is an active formation of facial morphology, which is directly related to the activity of the masticatory muscles. Therefore, it is very important to assess the condition of the masticatory musculature in order to timely identify imbalance in muscle activity, hypo and hypertonus of the musculature and to start therapy. Electromyographic study was performed on the Synapsis apparatus.
RESULTS. There is a violation of coordination in the work of masticatory muscles with predominance in the work in the right temporal muscle and left proper masticatory muscle. This is due to the fact that additional chewing was present in this group.
CONCLUSION. The provided analysis of masticatory function showed that children who frequently use chewing gum have a pronounced discoordination and imbalance in the work of masticatory muscles.

INTRODUCTION. For the correct diagnosis of hypertonicity of the chewing muscles, it is necessary to take into account the nature of pain, the restriction of opening the oral cavity and the data of additional research methods.
AIM. The aim is to develop a gradation of the severity of hypertonicity of the masticatory muscles based on clinical parameters and data from additional research methods – myotonometry, ultrasound and electromyography.
MATERIALS AND METHODS. 127 patients who sought dental care were examined, and the patients did not complain about the symptoms of myofascial pain syndrome. The diagnosis of masticatory muscle hypertonicity was verified in 90 people.
RESULTS. When studying the results obtained, statistically significant differences were revealed, which made it possible to develop a gradation of the severity of the above pathology into mild, moderate and high (grade I, grade II and grade III).
CONCLUSION. The application of the developed gradation will allow the dentist to develop a patient-oriented approach to the relief of muscle hypertension, depending on its severity, which, in turn, will improve the quality of life of this category of patients and reduce the cost of patients for muscle relaxant therapy.

INTRODUCTION. To increase the effectiveness of preventive procedures, it is important to choose the right professional hygiene products. The most common complaint after professional oral hygiene is hypersensitivity of the teeth.
AIM. To study the effectiveness of various polishing pastes.
MATERIALS AND METHODS. The research was conducted on the basis of the Department of Therapeutic Dentistry of the Research Medical University, Nizhny Novgorod, the cytological laboratory, Dental Polyclinic No. 1 (Ryazan). A dental examination was performed on 39 patients of both sexes aged 18 to 45 years with discoloritis of hard tissues, who were exposed to harmful industrial factors and did not have dental hyperesthesia. The control consisted of 13 practically healthy people who do not work in hazardous industries from Ryazan. The patients underwent professional hygiene using 3 types of polishing pastes (based on corundum, perlite, R.O.C.S. PRO POLISHING toothpaste), depending on which the patients were divided into 3 groups of 13 people each.
RESULTS. In all 3 groups, there was a significant difference in the values of IGZ, IRGZ, Schiff and VAS samples from the initial ones (p < 0.05), i. e. hyperesthesia of varying degrees appeared after professional hygiene. The most significant differences between IIGZ, IRGZ, Schiff’s sample and VAS were revealed in groups 1 and 3, the Schiff sample revealed significant differences between groups 1 and 2, differences in the values of IIGZ, IRGZ and VAS were also recorded in groups 1 and 2 of observation. The most pronounced hyperesthesia was observed when using Corundum–based polishing paste, and the minimum was R.O.C.S. paste PRO POLISHING.
CONCLUSION. The existing harmful production factors in workers lead to structural changes in the enamel. When carrying out occupational hygiene for people working in hazardous industries, the most preferable is the use of a paste based on ultrafine silicon dioxide.

AIM. Study the source condition of parodontal structures and local immunity of oral cavity besides flying composition of the civil aviation for the reason improvements of the algorithm treatment-preventive action of dentistry nature.
MATERIALS AND METHODS. Organized parodontology and immunology examination of the oral cavity beside 120 flying personnel on the base of physician-sanitary part of International airport Dushanbe. Examined contingent was divided into 5 groups: flight personnel with chronic gingivitis of the light degree of gravity; with chronic gingivitis of the average degree of gravity; with chronic parodontitis of the light degree of gravity; with chronic parodontitis of the average degree of gravity: checking group of the flying composition with sound parodont. They were researched particularities of the clinical current of the chronic gingivitis and parodontitis with using of hygienic and parodontology factors and immunology condition of oral cavity.
RESULTS. Inflammatory parodontal diseases beside flying composition with chronic gingivitis and parodontitis of the average degree of gravity (II, IV groups) runs more gravely, with expressed inflammatory reaction of near teeth tissues and disorders of the hygiene of oral cavity, in contrast with flying contingent I and III groups. At study of immunological conditions of oral cavity besides flying personnel of IV group revealed reduction of lysosome activity and increasing of immunoglobulin level that is indicative of reduction humeral protection of oral cavity.
CONCLUSION. Called studies have shown that PMA-index, bleeding and hygiene of oral cavity indexes with high degree of validity increased, but importance of the lysosome activity reduced on the base of increasing immunoglobulin of oral liquid beside flying composition with chronic parodontitis light and average degree of gravity.