Resorption of the jawbone may be seen in regions that have been without teeth for a long time. A base suitable for an implant application is prepared by increasing the bone volume with graft material and, in the posterior upper jaw, by raising the sinus floor. The maturation period of the graft varies from case to case. In some situations where bone loss is limited, the graft and the implant may be carried out in the same session; this decision is taken after radiological examination.