For two-piece PSIs, the framework will be designed with 3-4 mm endosseous projections at the anticipated area where the final abutments will be fastened, guided by the position of the teeth in the proposed prosthetic set-up. The endosseous projections will be designed in order to accommodate the height of the internal connection that will receive the final abutment in a second-stage surgery. Unlike single piece PSIs, bone-supported surgical guides will be designed to aid in the placement and seating of the two-piece PSIs corresponding to the preplanned osteotomy sites. The flap will be sutured in two layers; the muscle layer will be closed with 3/0 poliglecaprone resorbable suture material and the mucosa with 4/0 Polypropylene non-resorbable suture material.