The rehabilitation with dental implants in the patients with partial absence or total of teeth possesses extensive indications that are seen limited by biological and anatomical factors. The oseointegration arises like a discovered fact among the biological adaptation of the bone to the surface of the titanic of the implant (interface bone-implant) for which it is affirmed that the motive of failure of the majority of the systems of implants is that these it self envelop in a scar formation of fibrous tissue (Fibrointegration) badly differentiated what creates mobility, that carries to reactions in the mucous membrane and finally to the loss. The objective of the present article is to promote the presentation of patients' clinical cases with failure of dental implants, with the intention of clarifying the possible reasons and the helping factors of the above mentioned failure, and this way to improve the results in implantology.