The mechanical resistance of restorative materials is considered a relevant factor for the reconstruction of destroyed dental elements. Teeth and restorative materials are submitted to mechanical forces originated during the masticatory cycle. Therefore, it is fundamental to know the mechanical behaviour of the different restorative systems before their application. For the restoration of endodontically treated teeth with structural loss, it is common to use pin and core systems. They are produced by metallic or non-metallic materials, in different sizes and shapes. Even though they are a restorative alternative for teeth with structural loss and that have been submitted to endodontic treatment, failure of the tooth or of the system may occur. Thus, the clinical decision for a core and pin system should be based on knowledge of the mechanical properties of the material and the mechanical behaviour of the tooth when restored with these systems.