الخلاصة:
The study and use of nanostructured materials experiencing considerable growth due to their special
properties. All major types of materials are concerned: metals, ceramics, dielectrics, magnetic
oxides, polymers, etc. Due to their stability in the oral environment and almost perfect imitation of a
natural tooth, dental ceramics microstructured proven for decades. However, in the context of
research on new dental materials and still no metal in order to improve their intrinsic properties,
new dental ceramics nanostructuées are currently the subject of much research due to their physical
and mechanical properties. In this context we have worked on a glass-ceramic to basis of lithium
disilicate (Li2Si2O5) using IPS E-Max system to determined the mechanical properties of this
nanomaterial. For this, we have been used in the first party (party experimental) the diffractometer
(XRD) and the apparatus of the differential scanning calorimetry (DSC), in order to identify the
crystalline phase and measured the particle size. In the second part we have calculated some
mechanical properties such as elastic constants Cij, Young's modulus E, shear modulus G, bulk
modulus B and Poisson's ratio ν, using a calculation software based on the theory of functional
density, referred to as "DFT" (density functional theory) with the LDA and GGA approximation
