Objective. To present biomechanical substantiation of the possibility of using a post-resection obturator prosthesis made of polyamide thermoinjection material, dispersion-reinforced with nanostructured titanium dioxide.
 Materials and methods. The biomechanical method of mathematical modeling was applied in the work. The construction of the calculated finite element model included: determination of the mechanical properties of materials; construction of a geometric model; creation of a finite element grid; setting the boundary conditions of force effects.
 Results. Preliminary studies of the physical and mechanical characteristics of reinforced polyamide showed an increase in maximum stresses and Ung's modulus by 8,4 % and 7,2 %, respectively, which corresponds to the standards of ISO 1567: 1999. The results of biomechanical calculations of the strength of the elements of the prosthesis-obturator are the following: the level of maximum stresses within the strength indicators under horizontal load is 45,25 MPa, under vertical load (equivalent stress value) – 30,88 MPa, maximum stresses in the contact area with the occlusal pad – 35,00 MPa, deformations determined in the load area – 0,001, and the presence of retaining clasps distributes stresses on the surface of the supporting tooth and reduces them by 11 %. These facts determine a sufficient stability and good fixation of the post-resection prosthesis.
 Conclusions. Based on the results of physical and mechanical studies of the maxillary prosthesis-obturator made of thermo-injection polyamide reinforced with nanoscale titanium dioxide, the necessary strength characteristics and structures were determined, that indicates the prospects for its clinical application in the practice of an orthopedic dentist for the treatment of patients with acquired defects of the jaw bones.