Aim. To evaluate the antimicrobial efficacy of endodontic retreatment of patients with destructive forms of persistent periodontitis using a combined approach to disinfection of the root canal system and a hyaluronic acid medication.

Materials and methods. Group № 1 – endodontic retreatment with root canal disinfection by Hypochloran-3; group № 2 – the same, but for root canal disinfection, first "Hypochloran-3" was applied, and then photodynamic therapy using a 662 nm diode laser and a photosensitizer "ELOFIT®"; group № 3 – in addition to the manipulations carried out in group № 2, of the "Revident" medication was injected twice in the projection of the apical part of the causative tooth. Antibacterial efficacy was assessed according to the results of microbiological studies of biological samples taken before and 2 weeks after endodontic retreatment. The identification of microorganism colonies was carried out by mass spectrometry.

Results. In patients with destructive forms of persistent periodontitis, both before and after root canals disinfection, Enterococcus faecalis ranked the first in terms of the frequency of detection in biological samples, Candida albicans the second, and Veillonella parvula the third. At the same time, before the treatment of root canals, the predominance (more than 80%) of polymicrobial associations with their participation was shown. After root canal treatment, the number of obtained microorganism isolates in groups 1-3 significantly decreased: by 60.0%, 74.3%, and 76.0%. Against this background, the share of strict anaerobes and microaerophiles in groups 1-3 decreased: by 60.6%, 81.3%, and 78.1%. The share of facultative anaerobes also significantly decreased by 59.7%, 79.7%, and 83.8%.

Conclusions. Endodontic retreatment of patients with destructive forms of chronic periodontitis using combined disinfection of root canals both without and in combination with a hyaluronic acid medication is accompanied by a statistically significant reduction in species diversity, associations, and content of periodontal pathogenic microbiota.

Aim. Is the morphometric analysis of the working surfaces of endodontic rotating nickel-titanium instruments.

Materials and methods. The chemical composition and physical properties of the three types of endodontic rotating nickel-titanium F2 instruments have been analyzed: proptaper Universal (PTu, Dentsply, Maillefer, Ballaigues, Switzeland), Ultrataper (Eurofile, China) and Superfile (Eurofile, China) protapers. The evaluation of endodontic treatment of 75 endoblocks was also carried out.

Results. The research work shows that endodontic rotary instruments have both different chemical composition and heterogeneity of the alloy. The average comparable percentage of titanium and nickel in the studied alloy samples has been revealed. The quality of endodontic treatment of the endoblocks’ channels with various rotating nickel-titanium instruments is also comparable and meets the specified criteria.

Conclusion. The morphometric analysis has revealed a difference in the structure of the metal alloy of the F2 protapers, with a comparable content of nickel (46-52%) and titanium (38-41%). The content of pure nickel-titanium alloy along the periphery of the endodontic instrument in Universal protapers ensures high cutting ability of the faces. The obtained data on different resistance to cyclic loads should be taken into account in the endodontic treatment of multi-root teeth. The analysis of the structure of the nickel-titanium alloy indicates the predetermination of the development of the tool’s fracture with prolonged use and the need to take into account the cycles of the endodontic rotary tool.

Relevance. It is known that endodontically treated teeth have a lower survival rate compared to vital teeth. This is due both to changes in the hard tissues of the tooth, and to the use of inadequate technologies for their restoration. Therefore, the methods of restoration of such teeth are very relevant. But their application should be conditioned by their scientific substantiation using fundamental research methods, which determined the relevance of this study.

Material and methods. The study of the structural and functional characteristics of the restoration was carried out by scanning electron microscopy in the area of the restoration border, the border of the material-pin insert, the ledge area and the surface of the restoration material. For this purpose, 60 periodontal removed teeth with an IROPZ index of 0.8 or more were used, of which 120 restoration samples were made from the standard form of the composite and 120 restorations from the core-composite using a fiber-optic pin in both groups.

Results and discussion. In the course of the study, it was found that the data obtained in the study of the morphology of the restoration in group No. 1 indicate insufficient adaptive properties of the traditional form of the composite (porosity, cohesive fractures, violation of the marginal fit); The results of SEM testify to the advantages of the core-composite, which has a homogeneous, micro-rough, adhesive surface free from technical impurities, suitable for the use of all currently used methods of fixing an orthopedic structure.

Aim. To study the properties and resistance to cyclic loading of nickel-titanium files with a martensitic phase. The use of nickel-titanium instruments is an integral part of the endodontic treatment of root canals. During endodontic treatment, nickel-titanium instruments experience a huge load, which is manifested by fatigue of nickel-titanium instruments, in the form of a fracture.

Purpose. To determine the resistance of nickel-titanium files to mechanical, chemical and temperature stress.

Materials and methods. A nickel-titanium file with a martensitic S-flexi phase from Geosoft was selected as a study. Cyclic fatigue was determined using a simulation endodontic unit. Photo and video fixation was carried out as a calculation of the revolutions and breakage time of the tool in the process of determining cyclic fatigue. To assess changes in the structure of nickel-titanium instruments with a martensitic phase, electron scanning microscopy and determination of the elemental composition of the alloy were carried out.

Results. In the course of the study, tests were carried out to determine the cyclic load, close to the clinical reception. After a series of cyclic load detection tests, S-flexi files showed different resistance to cyclic load. The results of cyclic fatigue are summarized in Table 1.

Conclusion. High-quality and safe mechanical treatment of root canals is possible when using nickel-titanium S-flexi files. Due to the high resistance to mechanical, chemical and thermal stress.

Monolithic restorations are becoming increasingly popular due to the reduction of technical complications. The upper incisors are the most affected teeth due to their location and protrusion.

Aim. To determine the strength on models of incisors restored with monolithic crowns made of aluminum oxide and lithium disilicate.

Materials and methods. The finite element method created 2 models for the upper incisor. In the mesh model with an aluminum oxide monocrown, the number of nodes was 130185, the number of elements was 90934. In a mesh model with a lithium dioxide monocrown, the number of nodes was 130,000, the number of elements was 96,000. 3D models were built and analyzed in the ANSYS environment.

Results. In the alumina model, when loaded in the medial side (X), the horizontal and vertical forces were 0, in the vestibular side, the vertical force was -190 N, and the horizontal was 0, in the direction of the main axis of the tooth, the horizontal force was 15. In the lithium disilicate model, the maximum stresses mvM in dentin were 13.7 MPa, in cement – 18.5 MPa, in the crown – 61.8 MPa. Tensile, shear, and compression contact stresses at the adhesive interface between cement and dentin around the lithium crown and post were 11.9 MPa, 3.5 MPa, and 17.2 MPa, respectively.

Conclusions. A finite element analysis of an incisive endocrown based on aluminum oxide and lithium disilicate was successfully performed. Based on these results, an endocrown can be considered as an aesthetic and clinically feasible restorative approach for endodontic treatment of central incisors.

Aim. To assess systematically the available scientific evidence about the efficiency and the adverse effects of different solvents dissolving guttapercha.

Materials and methods. The study of publications was produced in the electronic databases such as Google Scholar, PubMed during a systematic review of the literature. Included articles contain information about using solvents during endodontic retreatment and their effectiveness and side effects. The publication date criterion was selected from January 2006 to January 2021.

Results. 66 articles were viewed during the review. After analyzing the literature for inclusion criteria, the total number of publications has become 13.

Conclusions. According to literature data, the frequency of using essential oils (orange oil, grapefruit oil, eucalyptus oil) to dissolve guttapercha in endodontic practice is increasing due to better biocompatibility and lack of cytotoxicity and carcinogenic effects.

Direct restoration is one of the most common methods of rehabilitation of defects in teeth hard tissues. Composite nano-ceramic restorations are an alternative to traditional prosthetic treatment in view of the growing demand for minimally invasive technologies, since crowns or other prosthetic restorations imply a significant loss of tooth structure with macro-mechanical and more invasive preparation of the dental tissues. This article represents a clinical case of direct composite restoration in carious teeth 3.6,3.7 with aesthetic and functional rehabilitation of contact points.

This case report describes palatal wall direct restoration with the stamp technique in Twenty-eight-year-old patient. The procedure was completed with the silicone index, transparent silicon and composite resin. After 5 years function patients was satisfied with the obtained functional result and had a wish to improve the adjacent tooth aesthetics.

The article considers nonsurgical and nonextraction   method of treatment of patient with skeletal class 2 malocclusion.

Aim. To evaluate the treatment effectiveness of Carrier Distalize, determing the short-term skeletal and dental effects occur as a result of Class II malocclusion correction utilizing the Carrière Overall, the Carriere Distalizer appears to be effective in early results in the treatment of Class II malocclusion.

Materials and methods: A 25 years old  male patient presented for treatment exhibition a class 2 malocclusion with a severely  retrusive  mandible  was treated with Carrier motion  class 2 appliance , after previous  orthodontic unsuccessful treatment with extraction of the lower right premolar by brace system. the appliance was used for 5 month fool time. This systematic review was conducted and changes were analyzed from dental photo protocol, lateral cephalograms taken at the start and after and study model measurements from pre and post treatment Results:  the time of  skeletal class two correction in class one  for Carriere motion appliance was significantly shorter.   great mesial mandibular movement and improvement in sagittal skeletal relation were shown after carrier motion appliance treatment for five month.

Conclusions. Treatment resulted that carrier motion appliance is simple to apply, comfortable for patient and affective in correcting class 2 malocclusion.

Aim. The thickness of bone tissue in patients with pathological dental inclinations planning orthodontic treatment with fixed equipment.

Materials and methods. The CBCT scans of patients with pathological dental inclinations was studied, bone tissue deficiency was described, a universal table was given that helps to calculate the necessary thickness of bone tissue at various levels of root length at the stage of treatment planning when the torc of the frontal teeth changes.

Results. Bone tissue deficiency is described in two study groups, however, in patients with retrusion, the deficiency is most pronounced in the cervical third from the vestibular side, in the group with protrusion, the deficiency is described in the cervical third from the oral surface in the cervical third.

Conclusions. The article describes a clinical case of orthodontic treatment using a universal table. The principle of operation of the universal table is shown, as well as its own clinical results proving the effectiveness of the universal table are described.

One of the express diagnostic methods is a crystallographic study of the oral fluid of this category of patients. Based on the quantitative and qualitative criteria of saliva obtained by the method of wedge dehydration, it is possible to non-invasively assess the effectiveness of the therapy and timely correct the prescribed treatment.

Aim. To conduct a comparative analysis of the crystallograms of the oral fluid in the dynamics of the treatment of patients with pathology of the oral mucosa.

Materials and methods. 90 patients were examined with a diagnosis of K12.00 aphthous stomatitis (small), chronic recurrent aphthous stomatitis (mild form). All patients were divided into 3 groups according to the methods of therapy 1:1:1 according to the principle of randomization. To assess the state of the oral fluid of patients with aphthous stomatitis against the background of various methods of treatment, the method of wedge-shaped dehydration was used, where the transition of a drying biological fluid into a solid state leads to a certain static order that can be observed and studied. Saliva was used as the material for the study.

Results. A qualitative analysis of the crystallograms revealed various types of structures with inclusions of bent prismatic crystals. Prismatic, fragmentary, curved, X-shaped, skeletal types of crystals were found throughout the entire field of view. At the same time, there was no clear structured picture as a result of a violation of the normal crystallization process.

Conclusion. There is a clear need for further research into the molecular etiopathogenesis of these conditions, which should allow the identification of more specific molecular targets for the development of diagnostic tests and therapeutic intervention. Based on the data obtained, the wedge dehydration method used for crystallographic examination of the oral fluid objectively reflects the state of the oral mucosa and can be used as an additional non-invasive method for diagnosing inflammatory and destructive diseases of the oral mucosa, as well as for correcting the treatment plan and monitoring the results of therapy.

Aim. To assess the neurological status of patients with malocclusion and temporomandibular joint dysfunction before and after splint therapy.

Materials and methods. Clinical examination, ultrasound examination and magnetic resonance angiography of the main head and neck vessels were performed in 37 patients with temporomandibular joint dysfunction caused by malocclusion aged 18 to 44 years.

Results. Physical weakness, apathy, memory impairment, sleep problems, hearing loss are markers of changes in cerebral circulation in orthodontic patients with temporomandibular joint dysfunction. The blood flow rate asymmetry along the medial cerebral arteries was found in the presence of asymmetry in the diameters of the vertebral arteries. 57.69% of patients showed vertebrogenic effects signs on the vertebral arteries in the intra vertebral segment (V2). There was no significant difference in the brain hemodynamics parameters before and after treatment with splint therapy.

Conclusions. Effective temporomandibular joint dysfunction treatment requires a comprehensive interdisciplinary approach.

The medical literature speaks about the influence of the oral cavity environment on the orthodontic archwires containing nickel (Ni) in their structure, causing corrosion of the archwires with the release of nickel ions into the patient’s oral fluids leading to its ingestion. If the nickel content in the body exceeds certain proportions, it is considered hazardous and can cause negative effects on the patient’s body.

Aim. To assess whether the clinical application of round thermoactive nickel-titanium (NiTi) archwires will risk increasing the concentration of (Ni) ions in the patient’s oral fluids within first two months of the orthodontic treatment.

Materials and methods. The Research was conducted on 17 patients, aged 14 to 27 years, fixed metallic orthodontic appliances were used for treatment. Using an atomic absorption spectrophotometer, oral fluid Samples were analyzed to determine the preliminary рН. Oral fluid samples were gathered from all participants of the study groups during different periods of time, observation was as follows: Before installation of fixed appliances, immediately after fixing the braces and tying up the thermoactive NiTi archwires, in 7 days, one month and two months after fixation.

Results. There were no statistically significant differences in concentration of (Ni) ions in first two months of treatment. However, in (25 %) of samples taken from patients in 1-2 months after the beginning of treatment a small increase in concentration of Ni ions (by 7,5 %) was observed.

Conclusions. It is improbable that a thermoactive NiTi archwire has a significant additional Ni load for patients undergoing orthodontic treatment.

Aim. To evaluate the effectiveness of anti-inflammatory and antimicrobial therapy in periodontal tissue pathology.

Materials and methods. 78 patients were examined. The results of treatment in 2 clinical groups were evaluated. Group 1 received traditional treatment; group 2 received therapy included local effects on the lymphatic system. The following methods were used in the study: clinical, radiological, bacterioscopic, cultural, immunological, expert assessments, mathematical statistics.

Results. A comparative analysis of the results of treatment of patients with periodontitis showed the effectiveness of local effects on the lymphatic system.

Conclusions. The data obtained allow us to conclude that in the clinical group of patients where local effects on the lymphatic system were used in the complex treatment of periodontitis, the effectiveness of therapy is higher, which is confirmed by the positive dynamics of clinical and laboratory indicators.

Relevance. The use of osteoplastic materials and hyaluronic acid in periodontology is extremely important for modern dentistry, since the predictive introduction of an osteoinductive drug and / or hyaluronic acid into the treatment protocol will allow simulating a state close to physiological, rejuvenating, and achieving the results of maximum restoration of periodontal structures.

Aim. To experimentally confirm the possibility of maintaining the physiological state and rejuvenating the periodontium using osteoplastic materials and / or hyaluronic acid.

Materials and methods. During the experiment, the dynamics of reparative osteogenesis in artificially reproduced defects of the jaw bones in rabbits was studied with the use of osteoplastic materials "Klipdent", "Bioplast-dent" or without the use of regeneration stimulants, as well as the morphogenesis of periodontal tissues when using hyaluronic acid. Results: the morphological studies carried out may indicate the acceleration of the regeneration processes in comparison with the normal course for 6-7 days.

Conclusions. It has been experimentally proven that the preservation and prolongation of periodontal youth is possible. We consider it appropriate and important in the conditions of modern dentistry, provided that the correct clinical strategy and tactical methods are chosen. In particular, the improvement of the procedure for open curettage of the periodontal pocket by predictively introducing an osteoinductive drug and / or hyaluronic acid into the treatment protocol will significantly increase the effectiveness of therapeutic measures and restore the periodontal condition close to physiological.