COMPARISON OF PHYSICAL AND CHEMICAL PROPERTIES OF OF A-SILICONE IMPRESSION MATERIALS

Abstract

The purpose of the study. To make a comparative assessment of the physical and chemical properties of the improved A-silicone impression material in comparison with its foreign analogues. Materials and methods of the study. Together with the accredited laboratory of dental materials of JSC “Stoma” in Kharkiv, Ukraine, the formulation of domestic A-silicone impression material of high and low viscosity was improved. A comparative assessment was made with the closest accredited analogues in Ukraine. For the study, 350 samples (15 samples of each material) were made to determine the physicochemical properties: microporosity, hydrophilicity, hydrophobicity, thixotropy, linear shrinkage, in accordance with ISO 4823.The following materials were used in the study: improved domestic A-silicone materials “ASІMD” and “ASІMV” produced by Stoma, as well as A-silicone materials “ASІMG” (Germany) and “ASІMI” (Italy). Scientific novelty. A-silicone impression materials are important in modern dentistry due to their physicochemical properties, which ensure the accuracy of impressions of teeth and oral cavities required for the manufacture of dentures and crowns. However, there are problems associated with linear shrinkage, which can lead to deformations and affect the correspondence between the impression and the final product. The hydrophilicity of these materials is also important: hydrophobic materials may not adhere well to wet surfaces, leading to the formation of air bubbles.At the same time, hydrophilic materials may be less resistant to mechanical stress. Temperature and humidity affect viscosity, cure rate, and can cause hydrolysis.Understanding these properties allows dentists to choose the right materials for clinical cases. However, issues such as linear shrinkage and the influence of external factors require further research and technology development.Ensuring high accuracy of impressions is critical for successful patient treatment, and further study may lead to the development of new, more effective materials.Conclusions. All the studied high viscosity A-silicone impression materials (type I) meet the requirements of ISO. ASІMD material showed the best results: the lowest microporosity (0.346%), the lowest linear shrinkage (1.23%), and hydrophobicity (32.3%). The high thixotropy of ASІMD (24.68%) ensures mold stability. Among the type III materials, ASІMD demonstrated the best performance: the lowest microporosity (0.121%), linear shrinkage (1.19%) and hydrophobicity (32.3%). The high level of thixotropy (24.68%) makes this material the most stable, which emphasizes its advantage for precise and stable prints.