[Evaluation of the duration of fixation of adhesive products in the treatment of traumatic lesions of the oral mucosa]. / Otsenka dlitel'nosti fiksatsii adgezivnykh sredstv pri lechenii travmaticheskikh porazhenii slizistoi obolochki rta.

OBJECTIVE: The purpose of this study was to evaluate the duration of fixation of adhesive films in the treatment of traumatic lesions of the oral mucosa. MATERIAL AND METHODS: The patients were divided into 2 groups. In the first group, the affected area was covered with an adhesive film with solcoseryl, in the second group with a film with vitamin E. The film was glued to the affected area according to the instructions, the time of gluing was recorded, patients were warned about the need to notify researchers via messengers or SMS messages about the time of peeling or resorption of the film. The evaluation was carried out by the method of variation statistics (Student's t-test for independent samples). RESULTS: The retention time of the film in the oral cavity was expressed in minutes, the average value in group 1 was 48.4±9.19, in group 2 - 127.70±49.07. Thus, the fixation of the film with vitamin E was longer than the films with solcoseryl (p=0.000180). CONCLUSION: Both films provided sufficient protective effect during the retention period. However, in clinical situations where a longer barrier protective effect to the damaged oral mucosa surface is required, it is advisable to use a vitamin E healing patch.

СOMPARATIVE SPECTROPHOTOMETRY ANALYSIS OF ZIRCONIUM DIOXIDE WITH THE CUBIC AND TETRAGONAL PHASE AFTER ARTIFICIAL AGING.

Aim - to evaluate optical features of the 3, 4 and 5Y-TZP zirconium dioxide with the spectrophotometry analysis under artificial aging procedure. For all experiments, identical standardized specimens of different types of zirconia with a diameter of 10 mm and a height of 1 mm were used. These types included Katana (Kuraray Noritake Dental, Tokyo, Japan) HTML (control) UTML, STML and ZirCAD Prime (Ivoclar Vivadent). Artificial aging (low-temperature degradation) was performed using the following autoclaving regime: 134 degrees Celsius, 2 atmospheres, 5 hours. A Shimadzu UV-3600 spectrophotometer was used to study the spectral characteristics of the provided samples. Since the samples have low bandwidth, it was decided to investigate the reflectance spectra. For this purpose, a Shimadzu SR-1503 integrating sphere was installed on the spectrophotometer. Results: All samples of Prime manufacturer show an increase in the reflected signal intensity in the range of 650-820 nm. This range corresponds to red and orange colors, which means that as a result of autoclaving the beige tint of the materials will become more pronounced. The intensity of scattered light of the sample UTML-glaze and STML-glaze has lower values in the whole visible wavelength range. However, the intensity decrease in this case is not uniform. In the range above 500nm the intensity decrease is more pronounced, which means that as a result of artificial aging the beige tint of the materials will become somewhat less pronounced. Zirconia restorations with a predominantly tetragonal phase with polished and glazed surfaces will not change reflectance during artificial aging.

EFFECT OF SURFACE TREATMENT PROTOCOLS OF ZIRCONIUM DIOXIDE MULTILAYER RESTORATIONS ON FUNCTIONAL PROPERTIES OF THE HUMAN ORAL MUCOSA STROMAL CELLS.

Aim - to study the effect of protocols of surface treatment of zirconium dioxide multilayer restorations on the functional properties of stromal cells of the human oral mucosa using molecular biological methods. For all experiments, identical standardized specimens of different types of zirconia with a diameter of 10 mm and a height of 1 mm were used. These types included Katana (Kuraray Noritake Dental, Tokyo, Japan) HTML (control) UTML, STML and ZirCAD Prime (Ivoclar Vivadent). DMEM/F12 growth medium (Paneco, Russian Federation) with addition of fetal calf serum (Gibco, USA) up to 10% and penicillin-streptomycin (Paneco, Russian Federation) up to 1% was used in the experiment. Cells were detached from the culture substrate with trypsin-EDTA solution (Paneco, RF) and their number and viability were assessed using an automatic counter TC-20 (Bio-Rad, USA). For repopulation, samples were transferred into wells of a 96-well culture plate (1 sample in 1 well) and cell suspension was layered at the rate of 12.5 thousand or 25 thousand live cells per well. After 48 hours, the cytotoxic properties of the tested samples were evaluated in vitro. According to the results of MTT test we can conclude that samples of ZirCad Prime and Katana UTML groups do not show cytotoxic properties (score "0" on the cytotoxicity scale according to GOST R ISO 10993-5-2009 "National Standard of the Russian Federation. Medical devices. Evaluation of biological effect of medical devices. Part 5. Studies on cytotoxicity: in vitro methods"). The samples of Katana STML group samples were slightly reduced compared to the control (about 12%), nevertheless, these samples can also be considered non-cytotoxic. Analyzing the direct contact with the material in all samples, a good occupancy of the material by cells was observed, in particular, the polished surface prevailed over the glazed one, however, this difference is not statistically significant. Analysis of human oral stromal cells to zirconium dioxide showed no statistically significant effect of different surface treatment protocols. However, the number of fibroblasts prevailed on the polished surface.

DETERMINATION OF CYCLIC FATIGUE OF A NICKEL-TITANIUM COXO SC PRO FILE USING A SIMULATION ENDODONTIC UNIT.

The use of nickel-titanium instruments during endodontic treatment ensures high-quality treatment of root canals. However, during instrumentation in the curved root canals of nickel-titanium instruments experience cyclic loading, which leads to their breakage. The splinter of the tool in the root canal makes it difficult for high-quality processing and obturation of the root canal, which is a very urgent problem. To carry out instrumental processing in canals with various anatomical and topographic features, the files must have phenomenal flexibility, lack of straightening of the canal, and have a safe non-aggressive tip. And for this reason, one of the most popular nickel-titanium COXO SC PRO tools was selected as a study, which, according to the manufacturer, have all the listed properties. The aim of the study is to determine the limit of resistance to cyclic loading and signs of breakage of the nickel-titanium endodontic instrument COXO SC PRO. Sterilization treatment, which is based on autoclaving, significantly reduces the strength characteristics of COXO SC PRO nickel-titanium files, which limits the use of these tools to one-time use without the risk of their breakage.

TREATMENT OF CHRONIC APICAL PERIODONTITIS: IN A SINGLE OR MULTIPLE VISITS? (REVIEW).

The article describes the effectiveness of the treatment of chronic apical periodontitis in one visit compared to multiple visits. A systematic review of the literature was conducted analyzing articles published on PubMed, Google scholar, ResearchGate and ScienceDirect between 2011 and 2021, treatment effectiveness was the selected outcome variable. A total of 21 articles were selected, 9 of which were selected for detailed review. Chief question in this article was: which treatment approach is more effective? Cleaning, Shaping, disinfecting and obturating in one visit? Or multiple (two) visit protocol? Chronic Apical Periodontitis is treatable in one visit, if done properly. Chronic Apical Periodontitis is treatable in one visit, if done properly, with proper shaping, disinfection, and proper hermetic obturation of the root canal. Bioceramic sealers showed the highest success rate out of all sealers used, the usage of 3-5.25% sodium hydrochloride and 17% ethylenediaminetetraacetic acid showed favorable results, although photodynamic therapy and ultrasonic activated irrigation showed outstanding results.

THE INFLUENCE OF FINISHING PROCESSING FEATURES ON THE POLYMERIZED COMPOSITE SURFACE STRUCTURE.

The purpose of this work is to assess the influence, feasibility and effectiveness of glycerin as one of the means that prevent the formation of an oxygen-inhibited layer, to search for the most effective polymerization protocol for the final portion of the composite materialThe prepared carious cavities of the first class were sealed with a composite, then the samples were degreased and dried. Since the dental material is a dielectric material and is highly susceptible to charging under the influence of an electron beam, it was decided to apply a thin (30 nm) layer of platinum to the surface of the objects under study.Studies of the surface of the teeth and the applied composite were carried out using a scanning electron microscope (SEM) Tescan Vega 3 SBH.Based on the essence of the mechanism of formation of the oxygen-inhibited composite layer, polymerization protocols were selected. The samples were divided into 4 groups according to each protocol of finishing processing.Based on the study of the surface of composite restoration using a scanning electron microscope (SEM) Tescan Vega 3 SBH, it is concluded that the most optimal protocol for finishing the restoration is polymerization using means that prevent the formation of an oxygen-inhibited layer, and subsequent finishing treatment. This method allows you to achieve a smooth surface of the composite, the absence of pores and microcracks, high-quality edge fit.

[Immunohistochemical study of Ki-67, PHH3, and CK15 protein expression in oral epithelial malignancy]. / Immunogistokhimicheskoe issledovanie ékspressii belkov Ki-67, PHH3 i CK15 pri malignizatsii épiteliia slizistoi obolochki rta.

OBJECTIVE: To investigate the expression of Ki-67, phosphohistone H-3 (PHH3), and cytokeratin 15 (CK15) proteins in the cells of the oral mucosa (OM) according to the degree of its malignant transformation. MATERIAL AND METHODS: OM biopsy specimens from 69 patients diagnosed with focal epithelial hyperplasia, intraepithelial squamous cell neoplasia, cancer in situ, and squamous cell carcinoma were examined. Tissue antigens were determined using mouse Ki-67 monoclonal antibodies, rabbit PHH3 polyclonal antibodies, and mouse CK15 monoclonal antibodies. RESULTS: There was an increase in epithelial proliferative and mitotic activities in squamous cell carcinoma and a sharp decrease in the expression of CK15 in the cytoplasm in cancer in situ and squamous cell carcinoma of the OM. CONCLUSION: The protein CK15 can be used for the differential diagnosis between high-grade dysplasia and OM epithelial malignancy at the stage of carcinoma in situ and squamous cell carcinoma.