[EXPERIMENTAL STUDY OF THE ULTIMATE STRENGTH OF SAMPLES OF MATERIAL BASED ON POLYLACTIDE AND TRICALCIUM PHOSPHATE, PRODUCED BY 3D PRINTING WITH DIFFERENT POROSITIES, DEPENDING ON THE TIME OF HYDRATION].

The advantage of polylactide-based implants is their rapid and complete biodegradation, followed by replacement of the defect with bone tissue. The disadvantage of materials with a high biodegradation rate is their low support ability. The admixture of ceramic materials increases the strength of the implants and reduces the rate of biodegradation. 3D printing technology allows you to reduce the negative factors of ceramic impurities through the manufacture of implants of various porosities. Target. Determine the ultimate strength of a composite material based on PLA and TCP, manufactured by 3D printing with different porosity options, depending on the duration of hydration. Were made 9 samples of material with a size of 10x10x10 mm with different porosity 40%, 30%, 20%. Samples of the material were hydrated in saline. Strength tests were carried out on days 2, 10, and 20 after hydration, 3 samples of material of each porosity. All samples were tested for compression. The carried out comparative analysis indicates that the tested samples are statistically significant (at the level of p <0.05) differ from each other depending on the value of porosity at all periods of hydration. Although the average values of the ultimate strength of samples of the same porosity tend to decrease depending on the period of their hydration, these changes do not acquire statistical significance even between the extreme periods of observation. This is confirmed by the values of the indicator of the statistical significance of the differences p equal to 0.07; 0.759 and 0.124 for specimens with porosity of 20%, 30% and 40%, respectively. The tensile strength of samples of material based on polylactide and tricalcium phosphate, made using 3D printing, directly depends on their porosity, the smaller the pore volume, the stronger the samples. The hydration of the samples in saline solution for 20 days does not entail statistically significant changes in their strength regardless of the pore volume, although the average values of the ultimate strength for all tested samples tend to decrease.