Mechanical behavior of silver alloys used as cast post and core in maxillary incisors

This experimental "in vitro" investigation is mainly concerned with the mechanical behavior of twenty plastic analogous simulating endodonticaly treated maxillary central incisor roots, divided in two groups, which were restored with: (i) silver (10 specimens, Ag - 80%); and (ii) silver - palladium (10 specimens, Ag - 58.5% / Pd - 27.4%) cast alloys. All the restored analogous were clamped inside stainless steel cylinders filled with acrylic resin, and were tested to failure in an INSTRON machine. The static compressive loads were applied with an inclination of 45° relatively to the longitudinal direction of the teeth. On average, the specimens restored with Ag- Pd presented higher values of final failure load (i.e. fracture or excessive plastic bending) and stiffness. On the other hand, those restored with Ag presented average proportional limit loads which were, in comparison, about 5% higher.