One of the most difficult sections of orthopedic prosthetic dentistry is edentulous jaws. Scientists say that due to severe atrophy of the alveolar processes up to 40% of patients have poor conditions for prosthetics. Obtaining impression is very important stage in the manufacture of complete denture that most closely reflects the surface of the hard and soft tissues located on the prosthetic area and its borders. According to the results of the study of professional literature and innovative developments in the problem under consideration it is revealed that the Czech Republic, Italy, Germany, USA, Ukraine and Russia are the leading countries in dental materials science. But what about silicone material that could be used to obtain compressive functional impressions for the manufacture of complete removable dentures? Unfortunately, there is a problem. The impression materials that are used by most dental practices have a low viscosity, which influences on the quality of the impression. In modern dentistry there is no group of C-silicon materials medium viscosity, which is necessary for high-quality impression of prosthetic area. Objective: to develop recipe and experimentally investigate silicon material medium viscosity for compressive functional impressions. Objects and methods. We together with the staff of accredited UkrSEPRO dental materials research laboratory of JSC «Stoma» create recipe and investigated the C-silicone material for functional impressions «Stomasil». The technical effect of our invention is achieved by changes of the qualitative and quantitative components of the recipe, by increasing the material’s plasticity, which improves its functional and clinical features. The plasticity of the material is their property of changing its shape under a load and retains the new shape after removal of the load. «Stomasil» is C-silicone impression material, vulcanizing by polycondensation under the influence of pasta-gel. For the preparation of the material we took necessary volume of paste, using a measured dosage scale planted under a glass plate, added the required amount of gel catalyst, as appropriate dosage scale. Then we mixed vigorously for less than 1 minute, filled forms, and investigated. Calculations were performed using the method of variation statistics for the Student – Fisher with a limit of confidence level p<0.05, methods of regression analysis, methods of comparison of mean values, the method of comparison of percent. The research results. When we developed the optimal composition of the new material we have studied three variants with different structure compositions of material. We selected the recipe that delivers the material the best physic-mechanical and toxic-hygienic properties for obtaining the functional impression. Improving the quality of the material for functional impressions we developed a material which consists of a synthetic rubber, aluminum oxide, barium sulfate with the addition of the dye. Synthetic rubber is low-molecular dimethylsiloxane liquid, which is stabled with active silicon oxide, hardening under the influence of cold curing catalysts. The plasticity is over a wide range of temperatures. Aluminum oxide is a compound of aluminum with oxygen, is used as catalyst of rubber. Barium sulfate is white powder, which increases the plasticity of the material. Then we have assessed the indicative properties of the samples (20 samples in each composition) in laboratory conditions on the research model. When we compared the experimental compositions of the new silicone material by their main properties you can define that the material which was made according to the «recipe № 2» has an optimal plasticity and hardness, which contributes to obtaining the accurate compressive functional impressions of edentulous jaws. Thus, the accuracy of the impression material, which was manufactured by «recipe № 2», is superior to the material on «recipe № 1» in 1.2 times and is superior to the material on «recipe № 3» in 1.3 times significantly (p <0.001). Only one material, which is made by «recipe № 2», according to their indicative properties, meets regulatory requirements and it is optimal for obtaining compressive functional impressions for the treatment of patients with edentulous jaws with complete removable dentures. Therefore, the materials by «recipe № 1» and by «recipe № 3» are excluded from the program clinical application. Conclusions Comparative analysis of the indicative properties of experimental compositions of a new silicone material medium showed that the material «recipe № 2» has significantly better indicative properties, and it is the optimum for obtaining decompressive functional impressions for the manufacture of complete removable dentures. Designed C-silicone material “Stomasil” for compressive functional impressions meets to the regulatory requirements according to main indicative properties TS U 24.6-00481318-041: 2005.
«Bulletin of problems biology and medicine» Issue 1 part 2 (127), 2016 year, 236-239 pages, index UDK 616.31(063)
