A series of mechanical strength tests have been carried out in order to characterize some dental implants. Most specimens tested were of the tapered-joint kind, but for comparison further tests have been carried out on screw-joined implants. The loads applied were similar to those existing in the typical working conditions of the component; however, in order to conform to the ISO standard 14801, loads higher than those achieved in working conditions were applied. The static characterization tests determined the strength of the system, with large deformations preceding rupture. The fatigue tests led to the determination of the fatigue limit of the dental implant, defined conventionally in these cases as the maximum value under which the system has a life of at least 2.106 cycles. The fatigue limit is higher than the stress that the teeth endure during the normal process of mastication, and it confirms the suitable structural design of the device. Failure analysis has shown that the fatigue crack leading to rupture commonly occurs in the section in which the hexagonal insert in the tapered joint begins.