difficult exo requiring sectioning of roots, buccal and palatal plates intact. Osteotomy underprepared, entry into sinus chamber and membrane perforation, placed prf fibrin membrane along with collagen membrane soaked in prf fluid at floor of sinus, packed a small amount of bone, placed a short and wide implant away from sinus floor, grafted remainder of socket with sticky bone from 90/10 mix of mineralized cortical/xenograft, grafted also distal crest region which is concave.