*2.2. Mechanical Properties of the Mouthguard Components*

The materials of the model are considered in elastic formulation. The elastic compression modulus (*E*) and Poisson's ratio (*v*) of enamel and dentine are shown in Table 1. Properties of dentine and enamel are taken from reference literature.

**Table 1.** Physical-mechanical properties of dental tissues.


The materials for the prosthetic inlay: CEREC Blocs (Sirona, Bensheim, Germany) is material 1; Herculite XRV (Kerr Corp, Orange, CA, USA) is material 2; Charisma (Heraeus Kulzer GmbH, Hanau, Germany) is material 3. The physical-mechanical properties of the inlay materials are presented in Table 2. The material properties for restoration are taken from reference literature [48,49].

**Table 2.** Physical-mechanical properties of the prosthetic inlay materials.


The most promising material for creating an inlay is considered to be fine-structured feldspar ceramic blocks of industrial production CEREC (material 1). The material is used to make inlays, onlays, crowns, and veneers. The minimum values of the cavity parameters for the inlay are selected according to the restrictions imposed on the material when milling.

For comparison, inlays from two different composite materials are considered. Herculite XRV (material 2) is a versatile microhybrid composite material. Charisma (material 3) is a radiopaque glass-based composite material.

1
