Background. Chronic apical periodontitis is an inflammatory disease associated with infection of the root canal and represents a major challenge in dentistry. Its prevalence is rapidly increasing among the adult population. The condition is characterized by variability in inflammatory responses and bone resorption. Genetic factors play a central role in its pathogenesis. Single-nucleotide polymorphisms (SNPs) significantly affect gene expression and protein activity. Recent studies highlight the importance of integrating genetic data into clinical dentistry.

Objective. To determine the role of intergenic associations of key genes involved in the modulation of inflammatory and immune responses in hereditary predisposition to chronic apical periodontitis.

Methods. A prospective single-center case control study was conducted from November 2024 to April 2025 at the Yaroslavl State Medical University (Ministry of Health of the Russian Federation) and the Medical Center for Diagnostics and Prevention “Sodruzhestvo.” The study involved 200 participants: 150 patients with chronic apical periodontitis and 50 healthy controls. The diagnosis was confirmed clinically and radiographically. Single-nucleotide polymorphisms of eight genes (IL-10, IL-1β, TNF-α, GSTP1, CYP1A2, TP53, COL1A1, and MMP-9) were analyzed using real-time polymerase chain reaction (PCR). Statistical analysis was performed using JMP Pro v.18.0 (SAS Institute Inc., https://www.jmp.com, 2024), Haplostats v.1.9.7 (Schaid, D.J., & Sinnwell, J.P., Software for haplotype-based association analysis, USA), and MDR v.3.0.2 (Multifactor Dimensionality Reduction, SourceForge, USA). The optimal models were identified based on the highest cross-validation consistency (CVC) and lowest testing balanced accuracy error. The significance level was set at p < 0.05. Results. MDR analysis revealed significant intergenic interactions associated with the development of chronic apical periodontitis. The three-locus model IL-1β×TNF-α×MMP-9 demonstrated the highest predictive value (balanced accuracy 79.8%, cross-validation consistency 10/10), highlighting the synergistic effect of inflammatory cytokines and proteolytic processes. Hardy–Weinberg equilibrium analysis showed deviations for CYP1A2 and TP53 in the chronic apical periodontitis group, suggesting an influence of environmental factors. The Fruchterman—Reingold graph confirmed a strong interaction between IL-1β and TNF-α, whereas COL1A1 displayed a moderate association. These findings indicate the multigenic nature of predisposition to chronic apical periodontitis and enable personalized diagnostics and therapy based on the combined genetic effects.

Conclusion. The results of this study may lay a foundation for developing personalized diagnostic and treatment strategies that account for individual genetic profiles. Integrating such approaches into clinical practice could improve disease outcome prediction, optimize therapeutic interventions, and reduce the risk of complications related to the pathological process.

Background. Advanced dental implantology requires not only a high level of surgical skill, but also comprehension on the patterns of tissue regeneration following immediate implantation. Particular emphasis should be placed on preserving the vestibular wall of the alveolus, as it affects the morphometric parameters of the mucous membrane, the width of the alveolar ridge, and the depth of the oral vestibule. This study aims to evaluate the clinical dynamics of these parameters in patients with different initial conditions.

Objective. To conduct a comparative analysis of changes in the parameters of the mucous membrane, alveolar ridge, and vestibular wall after immediate implantation in patients with different vestibular wall conditions.

Methods. A stratified clinical study included 80 patients who applied between January 2020 and January 2024 to the National Medical Research Center “Central Research Institute of Dentistry and Maxillofacial Surgery” with various clinical diagnoses for dental implantation in the maxillary anterior region. The patients were divided into three groups of 20 people each based on the degree of damage to the vestibular wall and the tactics used for dental implantation: Group I — sockets with an intact vestibular wall, conventional immediate dental implantation without bone grafting, using a connective tissue autograft; Group II — sockets with damage to the vestibular wall up to 1/3 of the length, dental implantation with bone grafting and the use of connective tissue autograft; Group III — sockets with damage to more than 1/3 of the length, dental implantation with bone grafting and regenerative materials was also performed. The control group (Group IV) included 20 patients who had teeth extracted 5–6 months prior to dental implantation. Assessments were made of the thickness of the mucous membrane, the width of the alveolar ridge, the distances from the neck and body of the implant to the vestibular wall, and the depth of the oral cavity vestibule before surgery, immediately after surgery, and at 1, 4, 6, and 12 months. Statistical data processing included calculating average values and assessing the reliability of differences. Differences were considered statistically significant at p ≤ 0.05.

Results. Patients in Group I had the optimal initial clinical conditions, with a mucosal thickness of 1.53 ± 0.11 mm and an alveolar ridge width of 9.80 ± 0.13 mm. However, after 12 months, a decrease in alveolar ridge width by 11.0% (p < 0.001) was observed. Group II (defect < 1/3) showed the highest increase in mucosal thickness (+65.2%) (p < 0.001) and improvement in the alveolar ridge width parameter (+8.9%) after 12 months (p < 0.001). Similarly, Group III (defect > 1/3) showed positive dynamics in mucosal thickness, with an increase of +58.9%, and alveolar ridge width, with an increase of +12.2% (for each indicator, p < 0.001). Meanwhile, the control Group IV exhibited a decrease in all indicators: mucosal thickness decreased from 1.41 to 1.10 mm, alveolar ridge width decreased from 6.16 to 4.34 mm, and oral cavity depth decreased from 6.4 to 4.8 mm. All differences were statistically significant (p < 0.001).

Conclusion. While the most favorable initial clinical parameters were observed in Group I, the most pronounced positive changes were achieved in Group II patients using bone regeneration techniques. These data confirm the high effectiveness of immediate implantation combined with plastic surgery for defects of the vestibular wall less than 1/3. Furthermore, the considerable impact of the initial clinical condition of patients on postoperative outcomes has been demonstrated, which emphasizes the relevance of a comprehensive assessment of tissue condition on the stage of treatment planning.

Background. Clinicians frequently encounter difficulties when selecting nickel-titanium instruments for specific clinical cases, primarily due to a lack of knowledge of what should be considered. Despite all the information available in the literature, the algorithm for making a decision is difficult to find. However, the bending angle and curvature radius of the root canal are known as essential factors to consider when diagnosing the anatomical and topographical features of tooth root canals during endodontic treatment.

Objective. To evaluate the strength properties of rotating nickel-titanium endodontic instruments by conducting a comparative experimental study on their resistance to cyclic fatigue.

Methods. A nonrandomized experimental study was conducted using two systems of rotating nickel-titanium instruments, the RM file (Rusmed, Russia) and ProTaper Universal (Dentsply Sirona, USA). Fusion 360 (Autodesk, USA) 3D modeling software was used to design root canal phantoms, which are blocks with a series of 5 channels for each instrument size, simulating a 45° root canal angle, a curvature radius of 5 mm, with a change in taper for each specific instrument, taking into account a magnification factor of 1.05. The following values were taken as the tip diameters for each instrument: S1 = 0.17 mm, S2 = 0.2 mm, F1 = 0.2 mm, F2 = 0.25 mm, F3 = 0.3 mm. Blocks with individual instrument sizes were made from metal using selective laser sintering. The blocks were fixed to a rigid canvas, and then the endodontic instruments under investigation were inserted through the canal openings along their entire length. Rotation was performed by an endomotor at a constant speed of 350 rpm, with a torque of 2.0 N/cm. Number of instrument cycles before failure was measured, recording the time of instrument failure. Next, surface wear of instrument fragments was studied using a JEOL JSM-7500F scanning electron microscope (Tokyo Boeki, Japan). The primary data base was created in Excel 2016 (Microsoft Corporation, USA). Hypothesis testing and sample comparison were performed using a JASP 0.19.1. open source software (JASP, Netherlands). Parametric criteria (Student’s t-test for independent samples) were used in the statistical data processing, and statistically significant differences were accepted at a level of p ≤ 0.05.

Results. For the RM file system, S1 instrument showed an average number of rotation cycles of 292.00 ± 38.45, with a minimum value of 227 cycles and a maximum value of 340 cycles. S2 instrument demonstrated higher performance with an average value of 345.00 ± 62.72 cycles, ranging from 266 to 438 cycles. F1 instrument exhibited an average resistance of 256.00 ± 31.92 cycles, ranging from 188 to 291 cycles. The lowest values among the RM file instruments were recorded for F2 (111.00 ± 48.34 cycles, range 40–184) and F3 (82.00 ± 26.55 cycles, range 43–130). For the ProTaper Universal system, S1 instrument showed the highest performance with a mean of 395.00 ± 38.12 cycles, with a minimum of 306 cycles and a maximum of 450 cycles. S2 instrument of this system had an average durability of 170.00 ± 21.55 cycles with a range from 144 to 202 cycles. ProTaper Universal F-series instruments demonstrated relatively low performance: F1 had an average of 72.00 ± 10.75 cycles (58–91), F2 with a 86.00 ± 22.06 cycle (60–120), and F3 with a 79.00 ± 26.33 cycle (38–116).

Conclusion. The data obtained demonstrate the advantage of the RM file system over ProTaper Universal in terms of resistance to cyclic fatigue. This system can be successfully used for treating complex root canals, including cases of pronounced curvature. Key factors in this case include using instruments within the manufacturer’s specified service life, maintaining optimal rotation speed, ensuring adequate irrigation, and controlling the force applied.

Background. In determining the dental status of a patient, the assessment of the jawbone tissue and the volume of bone structures are undoubtedly relevant focus areas. This process is instrumental in deciding on dental implantation, performing tooth-preserving regenerative procedures, treating periodontitis, selecting postoperative tactics, and making prognoses. In this article, spectral changes in bone tissue in periodontitis are studied using Raman spectroscopy as a diagnostic method that has been successfully applied in recent years to solve various biomedical problems.

Objectives. To evaluate spectral changes in bone tissue of the mandible alveolar region in patients with periodontitis.

Methods. A nonrandomized clinical and laboratory study was conducted in 45 patients aged 45 to 60 years at Samara State Medical University and the Center for Restorative Dentistry dental clinic of the Academy of Dentistry LLC. The control group (Group 1) included 17 bone tissue samples obtained from patients during surgical procedures on periapical tissues with an ICD-10 diagnosis of K04.5 and K04.8, in teeth with normal periodontium. The study group consisted of 28 samples of alveolar bone tissue from the lower jaw obtained from patients during procedures for chronic localized periodontitis diagnosed according to ICD-10 as K05.30, in teeth with periodontal pathology (Group 2). Raman spectroscopy was used to evaluate bone biopsies. Spectra were separated (deconvoluted) using the MagicPlotPro software (Magicplot Systems, LLC, Russia) for statistical analysis. The data obtained were analyzed using the IBMSPSS Statistics software environment (IBM, USA) by linear discriminant analysis (LDA) and comparative LDA analysis of groups.

Results. In patients with periodontitis, spectral changes in bone tissue are observed, which are related to changes in the relative intensity of Raman scattering lines. In linear discriminant analysis (LDA), the main spectral changes are also observed for the combination scattering spectra of bone tissue at 850 cm^–1 (proline benzene ring), 956 cm^–1 (v₁ P−O symmetric valence (PO₄^3–), 1069 cm^–1 (C−O planar valence (СO₃^2– v1)), 1172 cm^–1 (tyrosine, phenylalanine, C–H bond (protein)), 1315 cm^–1 (amide III (α helix)), 1385–1441 cm^–1 (scissor vibrations of CH₂ and bending vibrations of CH₃ in lipids and proteins), 1555 cm^–1 (amide II N–H), 1665 cm^–1 (amide I), 1745 cm^–1 (phospholipids), which correspond to the mineral and organic components.

Conclusion. Clinical and laboratory studies conducted to evaluate bone tissue in patients with periodontitis have revealed spectral differences from healthy bone tissue, which are manifested in the Raman scattering lines corresponding to the mineral-organic structure of bone tissue. Therefore, Raman spectroscopy appears to be a promising method for analyzing bone tissue condition in periodontitis. In the future, the data obtained may serve as a basis for optimizing approaches to periodontitis treatment.

Background. Laboratory monitoring and predicting are potential diagnostic tools for assessing the possible outcome of rehabilitation for patients with substance use disorder. The most promising indicators are considered to be those of the biochemical response to psychoactive substance use, including biomarkers of oxidative stress in mixed saliva.

Objective. To feature changes in oxidative stress markers in mixed saliva of patients with psychoactive substance and alcohol use disorder during the recovery phase.

Methods. The study was designed as an observational controlled study involving generally healthy men (Group 1, n = 20) admitted to the Clinic of Kuban State Medical University, patients with psychostimulant substance use disorder (Group 2, n = 20), and patients with alcohol use disorder (Group 3, n = 20). Group 2 and 3 patients had rehabilitation at the Narcological Dispensary No. 1 of the Ministry of Health of the Krasnodar Krai from March 2023 to November 2024. At the initial stage of rehabilitation and after 3 months, mixed saliva and venous blood were sampled to determine total antioxidant capacity, superoxide dismutase activity, glutathione peroxidase activity, and glutathione concentration. The data obtained were processed using AnalystSoft Inc. StatPlus software (Version 7). A one-way analysis of variance (ANOVA) with post hoc comparisons using Tukey’s criterion was used to compare the indicators. Statistically significant differences between the values of the indicators for the groups were accepted at p < 0.05.

Results. In the rehabilitation phase, mixed saliva analysis of patients with substance use disorders revealed an imbalance in oxidative homeostasis. Both groups of patients initially exhibited reduced total antioxidant activity and high activity of antiradical defense enzymes. After rehabilitation, both blood and mixed saliva had tendencies toward normalization of antioxidant activity, with a sharp decrease in superoxide dismutase and glutathione peroxidase activity. Mixed saliva oxidative stress markers correlated positively and statistically significantly with similar blood markers: total antioxidant capacity R = 0.35–0.46, superoxide dismutase activity R = 0.51–0.46, glutathione peroxidase activity R = 0.83 for Group 2 and 3 patients.

Conclusion. Mixed saliva oxidative stress markers can be used to develop algorithms for laboratory monitoring and predicting the rehabilitation of patients with psychoactive substance use disorder.

Background. Current advances in digital dentistry enhance the efficiency of rehabilitation for patients with missing teeth, while gradually replacing analog methods. The combination of cone beam computed tomography with intraoral scan data allows for precise virtual planning of surgical procedures thus minimizing deviations during implant placement. Furthermore, high precision in the placement of prosthetic structures is ensured. In this article, a clinical case study is presented to demonstrate a full digital protocol, which is becoming increasingly relevant in dental practice.

Clinical case description. This clinical case study reports on the total rehabilitation of a patient’s maxillary teeth. The cause of tooth loss was chronic periodontitis and its complications. After examination, the patient was diagnosed with ICD-10: K08.1: Loss of teeth due to accident, extraction, or local periodontal disease; K05.3: Chronic periodontitis. Tooth 1.3 was extracted, six implants were placed using a navigation template, superstructures (multi-unit abutments) were installed, followed by intraoral scanning of the jaws to make a temporary prosthetic structure. On Day 3 after surgery, a temporary structure was fixed in the oral cavity. After six months, a repeat intraoral scan was performed; a permanent screw-fixed prosthesis made of zirconium dioxide (without titanium bases) was prepared.

Conclusion. The clinical case described demonstrates a well-established approach to total maxillary rehabilitation using dental implants and a fully digital protocol. Digital technologies contribute to improving the effectiveness of implant treatment for patients, reducing the risk of complications, increasing patient comfort, and facilitating communication between the dentist and dental technician.

Background. In Russia, organizational commitment among nursing staff is given only a limited emphasis in the research literature. In contrast, since the 1960s, the global academic community has been considering commitment as a kind of quintessence that comprehensively reflects the attitude of public health workers not only toward their organization, but also toward their profession, employer, and work in general. Thus, commitment transcends the measurement of job satisfaction/dissatisfaction, loyalty/disloyalty to the organization, involvement/ non-involvement in its work, etc.

Objective. To examine the major approaches to comprehending organizational commitment among nursing staff through the foreign literature review, to identify the key stages in the development of this topic in historiography, and to explore the primary components and mechanisms of commitment formation in healthcare organizations.

Methods. Chronological, comparative, and critical analyses of publications (n = 3808) were conducted; the search query “organizational commitment of nurses” was used to select the publications from the English-language PubMed database of medical and biological publications.

Results. Four chronological periods of studying organizational commitment in foreign publications have been identified, differing both in content and in the focus of research. The publications of the first period (late 1960s/early 1970s to the 1980s) focused primarily on describing the characteristics of employees’ obligations to their organizations, their commitment to ethical models of behavior and occupational values. Along with these, the first studies were published that appealed for the development of “objective assessment systems for occupational health and safety programs” for healthcare workers, which would take into account various aspects of “working life,” “role ambiguity,” and “role conflicts” that affect the desire to work in a medical organization. The second period (1990s) involved the issues of engagement and job satisfaction as factors that define organizational commitment among staff. The necessity of involving nursing staff in the management of organizations was noted in publications analyzing “individual life experiences,” the introduction of psychological contracts and “co-management” models, and the creation of “independent nursing teams” and “joint teams.” In the third period (late 1990s/early 2000s to early 2020s), numerous publications appeared that aimed to measure the commitment of nursing staff using the model developed by J. Meyer and N. Allen. Of particular interest was the analysis of the “specificity” of nursing work in terms of shaping the “culture of institutions,” taking into account employee expectations, and creating an atmosphere of perceived support. The focus was on the emotional components of work, combined with a comprehensive study of emotional exhaustion, stress and stressors, professional burnout, depersonalization, etc. In addition, the process of expanding the geography of research was observed, with some attempts to understand the specifics of organizational commitment beyond the “Western experience.” The fourth period (since the early 2020s) involved the issues of workplace safety, collective emotional and professional burnout, and maintaining the “quality of health” of nursing staff. New topics included the impact of digitalization and multiculturalism on maintaining organizational commitment and stability among nursing teams.

Conclusion. The debates on the nature of organizational commitment and its qualitative measurement should not be considered closed, as real life constantly presents new challenges that require adequate study and detailed scientific analysis. The review results provide a basis not only for improving existing approaches to assessing organizational commitment, but also for developing comprehensive organizational development programs focused on retaining, motivating, and professionally developing nursing staff in Russian medical organizations.