Relevance. Currently, there are a large number of methods and instruments for the root canal system highquality biomechanical instrumental processing and subsequent obturation. In recent years, more and more scientific works in dentistry have focused on the fact that only 10% of root canals have no branches, and the classical canal has many additional canals. In this connection, the search for endodontic treatment methods that provide high-quality both the main and lateral canals obturation remains relevant.

 Aim was to increase the irreversible pulpitis treatment clinical effectiveness. 

 Materials and methods. We have carried out a comparative assessment of the root canals instrumental treatment effectiveness by reciprocation instrument followed by obturation using the vertical condensation technique in 15 patients with irreversible pulpitis. The comparison group consisted of 12 patients with chronic pulpitis, in the treatment of which the traditional machine rotary instruments technique of root canals and obturation using the lateral condensation method of gutta percha were used.

Results. Showed that the modern technologies use based on reciprocal instrument rotation with subsequent root canal obturation by the gutta percha vertical condensation method, is clinically justified, as evidenced by the comparative assessment data.

Conclusions. High technological effectiveness of the methods used in combination with low complication risks at the stage of instrumental processing and obturation provides the patient with maximum comfort in the postoperative period, as evidenced by the indicators of the verbal pain assessment scale, show minimal time spent on the procedure, which is important in the ergonomic work at the present stage . The endodontic treatment results of patients with the Reciproc and BeeFill systems use give reason to recommend their application in the dental practice. 

Relevance. The problem of preliminary depulpation of vital abutment  teeth under metal-ceramic constructions  is widely encountered in the daily practice of dentists. The decision on each clinical case is complicated by the presence of a number of arguments for each of the options for a treatment plan, namely the depulpation of the abutment teeth before prosthetics or preservation of their vitality.

Aim. To study the practical aspects of the problem of pre-depulpation of vital abutment teeth during prosthetics with non-removable metal-ceramic dentures.

Materials and methods. A two-stage survey of 335 dentists, students of advanced training courses at the Department of Dentistry IPO KrasGMU them. prof. V.F. Voyno-Yasenetsky (Krasnoyarsk) and analysis of the received questionnaires.

Results. As a result of the research, it was revealed that the expediency of preserving abutment teeth vital for prosthetics with non-removable metal-ceramic dentures has 5 positive sides (two of which are more fnancial and marketing than medical) than nine negative sides. It is diametrically opposed to the expediency of preliminary depulpation of vital abutment teeth before prosthetics with non-removable metal-ceramic dentures, which has 9 positive and 7 negative sides.

Conclusions. Thus, because of the  survey, we can conclude  that among dental  specialists,  the most preferable was  the preliminary depulpation of vital abutment teeth for metal-ceramic constructions, especially with increasing professional experience, which is also traced by the number of positive and negative sides of each treatment approaches.

Relevance. Oral cancer is a global problem in global health. The incidence of oral cancer remains steadily high. The occurrence and course of diseases of the organs and tissues of the oral cavity depend on the severity of somatic diseases. In turn, dental diseases can influence the course of somatic pathology, the development of focal diseases of the body. Therefore, there is a need for a multidisciplinary approach to the treatment of such patients and careful consideration of each nosological form in combination with concomitant diseases.

Aim. The structure of comorbidities and the state of the oral cavity in dental patients with cancer.

Materials and methods. The material of the study were:accounting and reporting forms of the Ivanovo Regional Oncologic Dispensary, case histories of inpatients. A screening examination of 68 patients with oncologic pathology of the oral cavity was conducted on the basis of the dispensary. 

Results. Among the comorbidities in dental cancer patients, cardiovascular diseases are in the first place (27.4%). The second place is occupied by chronic bronchitis (7.2%). In third place are the pathology of the gastrointestinal tract (3.9%), as well as endocrine pathologies (3.2%). Some patients in the past suffered cancer of other sites (cancer of the pharynx, lung, kidney). The share of neuropsychiatric disorders (epilepsy), infections (HIV) is small. During the screening survey conducted on the basis of the surgical and radiological departments of the Ivanovo Regional Oncologic Dispensary, it turned out that the main factors contributing to the development of tumor processes were: middle-aged people – poor oral hygiene (60%); sharp edges of damaged teeth (24%), poorly made restorations, fillings (16%); elderly people – poorly made orthopedic structures (86%). In individuals of all ages, smoking and alcohol consumption are the background factors.

Conclusions. The study allows us to conclude that somatic factors carry a significantly greater factor load in the elderly and elderly than in middle-aged patients. Dental status of patients affects the development of oncopathological processes in the oral cavity. Background conditions such as poor oral hygiene, poorly made orthopedic constructions and restorations play an important role in the oral health of the oral cavity.

Relevance. D ental i mplantation i nflammatory c omplications o f a re r ecently o ne o f t he m ost i mportant and challenging problems in dentistry.

Aim. Is assessment of the species composition of microbial associations in patients with complications of dental implantation and analysis of their sensitivity / resistance to antibacterial drugs.

Materials and methods. Susceptibility of clinical isolates in all the examined patients (37 people) by bacteriological method was defined. Bacteroids, fusobacterium and stepococci were mainly allocated as pathogenic bacteria. In 1/5 of cases S. aureus, S. epidermids, including MRSA and MRSE was allocated.

Conclusions. The antibiotics for treating dental implantation complications remain amoxicillinum/clavulonat, lincosamide (clindamicinum) and fluorqunolones.

Aim. Compare the effectiveness of dental instrumentation with a C-shaped root canal system with two different endodontic systems: XP-endo and Gentlefile.

Materials and methods. The study was performed on 30 teeth removed by medical reasons (18 premolars and 12 second molars of the lower jaw). Samples were divided randomly into 2 equal groups. Separately, three C-shaped mandibular premolars were processed with XP-endo and Gentlefile systems and manual steel files for scanning electron microscopy. For comparison, one rough premolar was taken. The C-shaped configuration was confirmed by cone-beam computed tomography. The quality of endodontic treatment of root canals was assessed by the microstructure of the surface of the root dentin using a scanning electron microscope, as well as the depth of penetration of the dye into various zones of the root dentin. When working with the XP-endo system, the mean value of the area of stained dentin in the apical third was 11.56 ± 3.15, in the middle – 37.65 ± 9.3, in the coronal – 45.3 ± 12.3. In the Gentlefile group, the painted area of root dentin in the apical third was on apical 3.5 ± 1.39, in the middle- 8.5 ± 2.42, in the coronal – 12.8 ± 1.65. Differences are significant (p ≤ 0.05). SEM photographs of samples of the treated Gentlefile showed coarser dentinal surfaces, the presence of a smeared layer, fewer open dentinal tubules than by XP-endo.

Results of the study showed that the endodontic system XP-endo better treats the surface of the dentin root canals with the C-shaped configuration, compared with the Gentlefile.

Aim. Determine the nature of the changes of the crystal lattice of nickel-titanium instruments Protaper Universal in the process of repeated autoclaving based on the results to conclude about the influence of multiple sterilization on the characteristics of clinical use of protaper.

Materials and methods. is endodontic nickel-titanium instruments of Protaper Universal 21 copies. The instruments were divided into 3 groups of 7 samples, x-ray elemental examination and x-ray diffraction analysis were performed after 1, 4 and 7 cycles of autoclaving at 1340c, pressure 2 bar (1.9 ATM.), time 26 minutes.

Results. According to x-ray diffraction, the samples are an alloy of the Ni-Ti system and a material containing iron (presumably steel). In addition to nickel and titanium, iron, chromium, cobalt and zinc were found. With increasing number of repeated autoclaving cycles, the mass fraction of Fe, Co, Zn, Cr is decreased, followed by the disappearance of Fe, Co and Zn. Probably the addition of steel affects the cutting ability of the protapers. Consequently, with a decrease of steel content, the cutting efficiency of nickel-titanium protapers also decreases, which negatively affects their cleaning ability. According to the results of the second study, it was found that with increasing autoclaving cycles, the percentage of Fe is decreased, there were changes in the three obtained diffractograms, which indicated an increase in the number of martensitic phase and a decrease in austenitic.

Conclusions. The accumulation of such a fragile and unstable structure as martensite can lead to a decrease in the strength of the material to torsion force and lead to breakage of the instrument during the use. The cutting efficiency of the protapers is also reduced during repeated sterilization cycles, which can be caused by the austenitic and martensitic phase displacement affecting the mechanical properties.

Relevance. In the most cases periapical pathology is caused by intra-canal infections and its initial treatment is by conventional endodontic treatment. Endodontic failure is usually associated with technical limitations that prevent adequate intra – canal microbial control in the complex microanatomy of the root canal system. Even after the endodontic retreatment, owing to the factors of complex internal microanatomy, the failure may persist. In these clinical situations, apical microsurgery has been proven to be alternative for the clinical treatment of these infections. Various technological advances in the area of apical microsurgery have occurred in recent years. It is very important to obtain apical seal. With this purpose mineral trioxide aggregate (MTA) are widely used in dentistry.

Aim. To evaluate and compare the fill density of mineral trioxide aggregate (MTA) produced by mechanical and manual mixing as well as the effect of sonic and ultrasonic (indirect activation) agitation during placement.

Materials and methods. There were 30 acrylic transparent blocks with 30 -degree curved canals (Dentsply) used. All blocks were pre-weighted to the nearest 0,1 mg using a digital electronic balance (Model CPA225D-0CE, Sartorius, Gottingen, Germany) and then instrumented using Wave •OnePrimary 025.08 (Ni-Ti) rotary file (Dentsply) on the working length 16 mm. During instrumentation each canal was irrigated with 1 ml of water. Upon completion of instrumentation, the canal was dried with paper point. Each instumented block was weighted again. All blocks were randomly divided into 6 groups (with 5 specimens in each group) and obturated with different techniques with MTA which was also prepared by mechanical and manual mixing: 1st group – MTA manual mixing and insertion into the canal using N-Ti plugger; 2nd – manual mixing and sonic condensation, 3rd – mechanical mixing and manual insertion with a plugger, 4th – mechanical mixing and sonic condensation (2 s), 5th – manual mixing and sonic condensation (2 s), 6th – manual mixing and indirect ultrasonic condensation (2 s). In our experiment we used belarussian MTA (Rootseal, Belarus). After MTA setting all blocks were weighted. We used the weight of the MTA as an indicator of fill density because the formula for density is: Density = Mass/Volume.

Results. Mechanical mixing of MTA and its sonic condensation during 2 s resulted in a greater fill density than that achieved using manual mixing and conventional insertion (with Ni-Ti plugger).

Conclusions. Although manual mixing and conventional insertion of MTA are usually used by dentists, these techniques were not associated with a significant advantage in term of fill density over mechanical mixing and sonic condensation during short period of time (2 s).

Relevance. The use of fiber posts in the post-endodontic restoration is widespread among dental practitioners. However, one of the key disadvantages of this technique is the poor adhesion between the posts and luting cements. The use of various chemical solutions for surface pretreatment, in particular, 37% hydrogen peroxide, makes it possible to achieve acceptable values of adhesion.

The goal is to compare the efficiency of fiber post pretreatment with various chemical solutions and to develop an optimal pretreatment protocol.

Materials and methods. Evaluation of the adhesive bond strength of the 370 fiberglass pins of 3 different types with 2 types of luting cements, was carried out by torqueout test. Posts were divided into 18 groups depending on the pretreatment method.

Results. The highest values of adhesive bond strength were achieved after post treating with concentrated hydrogen peroxide for 10 minutes, followed by silanization.

Conclusions. Fiber post pretreatment before luting procedures with chemical solutions that contribute to the dissolution of the polymer matrix increases the adhesive bond strength compared to the control group without pretreatment.

Relevance. The forecast of the functionality of the tooth after endodontic treatment, when resistance to mechanical loads is significantly reduced, depends on the choice of method and material for the restoration.

Aim. The aim of the work was to compare the physicomechanical and clinical qualities of composite materials used to restore posterior teeth after endodontic treatment.

Materials and methods. Studies were carried out according to GOST 31574-2012 – determination of the curing depth, strength with diametral rupture, bending and determination of water absorption and water solubility, as well as the integrity of the restorations, the presence of chips, the development of secondary caries after 24 months.

Result of research. Based on a comparison of the physicomechanical and clinical qualities of the composite materials Tetric EvoCeram (Ivoclar Vivadent) and SDR (Dentsply) used to restore the posterior teeth after endodontic treatment, as well as the timing of the time spent on treatment, the choice of a composite material for the restoration is justified.

Conclusions. Indicators for all the parameters studied composite materials Tetric EvoCeram and SDR more perfect than required by GOST. The time spent on the restoration of the posterior teeth using a two-layer technique using the composite SDR as the basis and restoring the occlusal surface with the Tetric EvoCeram composite is significantly on average 10 minutes less than with a tooth restoration using the multilayer Tetric EvoCeram composite material ( p ≤ 0.05).

Relevance. Currently, an odontogenic anomaly of tooth development, which is referred to as a bump on the crown surface of the affected crown, is encountered more and more often at the dental reception. and premolar Leong. Often this malformation is combined with spatula incisors (talon cusp). The prevalence of this strain in the Asian group of the population, whose representatives in the territory of the Russian Federation constitute a significant part of the population, makes it necessary and relevant knowledge of this pathology by dentists.

Aim is to draw the attention of dentists to the features of treatment of Dens evaginatus due to the high prevalence of this pathology.

Materials and methods. The paper describes the clinical cases of patients with Dens evaginatus (DE) with a description of the treatment plan in order to prevent the development of complications at the dental admission with the wrong approach to the treatment of this pathology. A comprehensive examination and treatment of patients was carried out, in accordance with the data obtained using CBCT, a treatment plan was drawn up. The main treatment method for DE is to prevent erasing and breaking off the DE bump, especially in teeth with unformed roots.

Results. The obtained results indicate a high prevalence and frequency of occurrence of this pathology at the dental admission, which, if improperly treated, may cause complications leading to loss of viability of the tooth pulp.

Conclusions. Based on the results of the study, it can be concluded that C-shaped channels are often found in the lower premolars in the Asian group of the population, which present the greatest difficulty in endodontic treatment. 

Relevance. Gutta-percha has long been successfully used in endodontics for root canal obturation. It is promoted by its biological inertness in relation to oral and dentin liquid, plasticity, possibility of application in cold and in hot technologies of sealing.

Aim. To study the modern scientific literature devoted to the use of gutta-percha in Endodontics. Results. Gutta-percha was, is and, apparently, will remain one of the most popular materials for root canal obturation in endodontic treatment for a long time.

Conclusion. It is necessary to continue to improve methods of obturation of root canals of gutta-percha teeth and ways of giving it antimicrobial properties.