COMPARATIVE ANALYSIS OF ENDURANCE CEMENTS FOR THE FIXATION OF NON-REMOVABLE ORTHOPEDIC CONSTRUCTIONS UNDER THE ACTION OF CYCLIC COMPRESSION.

OBJECTIVE: The aim: To conduct studies of the physical and mechanical properties of cements for fixation, namely the duration of cement samples under cyclic compression. PATIENTS AND METHODS: Materials and methods: We have conducted a study of 6 cements for permanent fixation of fixed structures of dentures. To study the duration of cements under cyclic compression, a special stand was used, which allows testing samples for cyclic compression with a load frequency of 5.4 Hz or 324 cycles per minute and an increase in compression in a cycle from 10 to 100 kg/s. RESULTS: Results: Comparative analysis of the mechanical properties in compression of dental cements for permanent fixation showed that the obtained deformation curves differ significantly in each of the cement samples used in the study. CONCLUSION: Conclusions: The results of the study of the physical and mechanical properties of cements indicate that the most optimal complex of properties is possessed by the zincphosphate cement Unitsem and glass ionomer cements Cemion and Fuji I. This is most clearly confirmed when studying the duration of cement samples under cyclic compression, which simulates a real situation.

CHARACTERISTICS OF METAL ALLOYS PROPERTIES FOR DENTAL CASTING AFTER THEIR REPEATED REMELTING.

OBJECTIVE: The aim: To study clinical and experimental substantiation of the possibility of using cobalt-chromium and nickel-chromium alloys after repeated remelting for non-removable one-piece prosthetics. PATIENTS AND METHODS: Materials and methods: Experimental studies of Remanium GM 700 and Remanium CSe dental alloys have been carried out. To study the physical and mechanical properties of alloys, samples were obtained by sequential six-fold remelting in a Tiegelschleuder TS casting dental unit manufactured by Degussa. All samples were subjected to chemical analysis and metallographic studies by methods generally known in metallurgy, which included studies of microhardness, elasticity, tensile deformation, bending deformation and alloy structure after repeated remelting. RESULTS: Results: Thus, the obtained results of the chemical, physicomechanical and structural properties of the remelts indicate that the Remanium GM 700 and Remanium СSe alloys can be reused many times for the manufacture of one-piece orthopedic structures in that they are identical with certified alloys. CONCLUSION: Conclusions: In terms of structure, qualitative and quantitative composition of elements, physical and technological properties, the Remanium GM 700 and Remanium CSe alloys have been repeatedly remelted meet the requirements of materials used in biologically active environments of the patient's body. High-quality and cost-effective remelted multiple times Remanium GM 700 and Remanium CSe alloys can be recommended for use in practical prosthetic dentistry six times.

COMPARATIVE EVALUATION OF HISTOTOXICITY INDICATORS OF METAL ALLOYS FOR THE MANUFACTURE OF METAL CERAMIC DENTAL CONSTRUCTIONS.

OBJECTIVE: The aim: To carry out a comparative assessment of metal alloys for the manufacture of metal-ceramic constructions of dentures by determining the indicator of their histotoxicity. PATIENTS AND METHODS: Materials and methods: To identify the effect of metal alloys on cobalt and nickel bases on the tissue of organism, we carried out an experimental-morphological study of standard samples of metal alloys "Shot-alloy", "Remanium-2000", "Cerium", "Dent-NCB", "Cellite-N". RESULTS: Results: A careful histological analysis of the capsules formed around the metal alloy samples during two periods of the experiment showed that the healing time of the subcutaneous tissue was not the same. The most complete healing, that is, the formation of mature fibrous connective tissue, occurred during the implantation of the cobaltbased alloy "Remanium-2000" and the capsule formed at the end of the experiment around the implanted sample from the "Shot-alloy" alloy, and during the implantation of the "Cerium" alloy, healing the wound surface and the formation of a connective tissue capsule occurs fully than in previous cases. CONCLUSION: Conclusions: The analysis of the performed experiment testifies in favor of the point of view that the speed and quality of healing of damaged subcutaneous tissue upon the introduction of implanted research alloys depend largely on the individual chemical components that make up the alloys, or on their combination.

Comparative assessment of the state of bone resorption in patients with chronic generalized periodontitis according to orthopantomogram and cone-beam computed tomography.

AIM: The aim of the study was to assess bone resorption in patients with chronic generalized periodontitis according to orthopantomogram (OP) and cone-beam computed tomography (CBCT) and substantiate which of these methods is the most appropriate for use. MATERIALS AND METHODS: In order to compare the objectivity of the results of examining the periodontal bone tissue by the above methods (panoramic radiography and computed tomography), we analyzed 26 panoramic radiographs and computed tomograms of the same patients, performed on a PICASSO (3D) computed tomograph by «Vatech¼. RESULTS: Comparison of CBCT and OP data in patients with periodontal tissue disease showed a significant difference between the indicators of bone tissue resorption in the mesiodistal direction, and revealed that the volumetric image is significantly objective X-ray picture in periodontal diseases by identifying the state (resorption) of the vestibular and oral cortical plates in any section dentition. At the same time, only according to CBCT data, an objective assessment of bone resorption in the vestibulo-oral direction is likely. CONCLUSIONS: Mesiodistal CT and orthopantomographic data do not match well enough. They allow with high accuracy to identify areas of resorption only from the medial and distal sides. However, the vestibulooral CT projection indicates the bias of a two-dimensional image for obtaining an accurate X-ray picture of the state of the alveolar bone and a complete assessment of bone resorption.

EPIDEMIOLOGICAL INDICATORS OF DENTAL MORBIDITY OF CHILDREN AS AN INDICATOR OF ADVERSE ENVIRONMENTAL INFLUENCE.

OBJECTIVE: The aim: Is to study the ecological and hygienic situation in the living area of 6-year-old children in terms of drinking water (micro- and macroelements), to identify its relationship with the state of mineral metabolism in children's mouths, prevalence and intensity of temporary and permanent caries. PATIENTS AND METHODS: Materials and methods:Clinical and laboratory studies were to study the objective condition of the teeth -intensity of dental caries according to the recommendations of the WHO and the method of T.F. Vinogradova. The hygienic condition of the oral cavity was determined by the indices Silness-Loe, Stallard. RESULTS: Results: The results of our studies have shown that the proposed therapeutic and prophylactic complex, which includes drugs of endogenous (Vitafluor) and exogenous use (osteovitis, deep fluoridation, toothpastes "Splat junior" and "Lacalut fluor"), improves the hygienic state of the oral cavity, increases mineralizing the potential of the oral fluid and, as a result, helps to reduce the intensity of dental caries in children. CONCLUSION: Conclusions: The data obtained indicated a high caries prophylactic efficacy of the proposed therapeutic and prophylactic complex for 6-year-old children living in the zone of hypophtorosis.

INITIATING FACTORS OF COMPLICATIONS DEVELOPMENT DURING PROSTHETICS OF TEETH WITH FIXED PROSTHESES.

OBJECTIVE: The aim: Determination of the factors complications occurrence in prosthetics with metal-ceramic prostheses. PATIENTS AND METHODS: Materials andmethods: Clinical, cytological, cytochemical methods and methods of statistical processing of the received data are applied. RESULTS: Results: A number of factors with different degrees of significance have been identified, which in the dynamics of clinical observations of the percentage of absorbed dispersion are decisive in the development of changes in the gums. At the stage of odontopreparation - the 1 factor, with the percentage of absorbed dispersion (12,3%) - preparation. The 2 factor - (11,9%) - traumatic. The 3 factor, periodontal, was slightly less significant (9,8%). In the dynamics of clinical observations for 45 days in the first place was the dissecting factor - (14%). The second most important factor was the vitality of the teeth - (11,5%). The 3 factor remained relatively stable - periodontal (8,5%). In the dynamics of clinical observations after 1 year, a redistribution of significance was noted. The largest percentage of absorbed dispersion covered periodontal factor - (15%). Vitality factor - (11%). Slightly lower, but clinically significant, of (8%) absorbed dispersion, was the preparation factor. CONCLUSION: Conclusions: Statistical analysis of the studied parameters made it possible to determine the key factors for predicting their development and diagnostics, it is important for organizing an increase in the effectiveness of orthopedic prophylactic therapeutic measures at the stages of restoration of dental hard tissues.