The paper considers a new technology for the treatment of non-carious cervical lesions (NCCLs). The three parameterized numerical models of teeth are constructed: without defect, with a V-shaped defect, and after treatment. A new treatment for NCCL has been proposed. Tooth tissues near the NCCLs are subject to degradation. The main idea of the technology is to increase the cavity for the restoration of NCCLs with removal of the affected tissues. The new treatment method also allows the creation of a playground for attaching the gingival margin. The impact of three biomaterials as restorations is studied: CEREC Blocs; Herculite XRV; and Charisma. The models are deformed by a vertical load from the antagonist tooth from 100 to 1000 N. The tooth-inlay system is considered, taking into account the contact interaction. Qualitative patterns of tooth deformation before and after restoration were established for three variants of the inlay material.

This paper deals with direct restorations of teeth with non-carious cervical lesions (NCCL). NCCL defects are capable of gradual growth and are accompanied by the degradation of the surrounding tissue. Direct restorative treatment, in which the cavity is filled with a cementing agent, is considered to be an accessible and common treatment option. The study included simulations of the teeth without lesions, the teeth with V and U lesions and the tooth-restorative system. Parameterised numerical tooth models were constructed. Two cases with defect depths of 0.8 mm and ~1.7 mm and three variants with fillet radii of the defect end of 0.1, 0.2 and 0.3 mm were considered. The effect of two biomaterials for restorations was studied, namely Herculite XRV (Kerr Corp, Orange, CA, USA) and Charisma (Heraeus Kulzer GmbH, Hanau, Germany). The models were deformed with a vertical load of 100 to 1000 N from the antagonist tooth. The tooth-restorative system was considered, taking into consideration the contact interaction in the interface areas with the tooth tissues. Within the limits of the research, the character of the distribution of the deformation characteristics and their dependence on the level of loading, the depth of the defect and the radius of the curvature of the “wedge” were established.

The article addresses the modeling of the process of manufacturing a large-sized shell, given the thermomechanical behavior and viscoelasticity of the composite mandrel. The results of the experimental identification of viscoelasticity parameters of the examined material are presented. A numerical algorithm for adapting the experimental data for the ANSYS Mechanical APDL finite element analysis package is proposed. A Prony series expansion of the relaxation kernel is used as a model for describing the material behavior. The effect of temperature on the rate of relaxation processes is taken into account through the application of a temperature-time analogy according to the Williams–Landel–Ferry formula. The selected model with the calculated parameters was implanted into the commercial package of ANSYS Mechanical APDL. Simulation of two process steps of manufacturing a large-sized product was performed: winding and heat treatment of the shell. For this purpose, the quasistatic problem of mechanics and unsteady thermal conduction under conditions of convective heat transfer were solved by the finite element method. The influence of thermomechanical behavior of the mandrel material on the normal pressure acting on the mandrel surface as a function of temperature and force factors was estimated quantitatively and qualitatively. It was found that with respect to the nonlinear behavior of the composite material, the pressure level decreases by 50% compared to the case of using models of elastic behavior. This result justifies the importance of using complex models of material behavior in studying long-term technological processes, especially those associated with high-temperature effects.