Method for expanding bone crest (1) in order to receive the installation of a final dental implant (4), where the bone crest (1) is expanded using a implant-expander, in other words, a biocompatible and osteoconductive piece that has an expander function. The use of an implant-expander (3) to widen the bone crest (1) has the important effect of said implant-expander acting as a support to the bone and therefore helping to consolidate the fracture of the bone crest (1) and the formation of bone around said implant-expander. The bone generated around the implant-expander (3) is therefore of a high quality. The invention also contemplates the optional correction of the angulation of the alveolus during the widening process, so that the final dental implant (4) and the corresponding dental prosthesis are adequately oriented. It is also an object of the invention to provide a specific design for the implant-expander (3).