If the implant is removed, probe the wall and the roof of the osteotomy.  If the sinus floor remains defective, insert PRF membrane prior to bone graft and implant.  A week later, the healing abutment is removed; the implant is not loose; the mesiobuccal gingiva slightly erythematous (Fig.4).

Drill Perforation Last Next Xin Wei, DDS, PhD, MS 1st edition 03/21/2018, last revision 09/06/2018