In fact the designed initial drills do not get to the bone with guides.  After use of the next length drills (1.5 mm longer with sharp end), the sinus floor perforates without membrane perforation.  Once 3.5 mm drill is used following sequential osteotomy, a 4x10 mm dummy implant is placed for sinus lift with 1 mm short of the depth and >50 Ncm.  Following the dummy implant removal, allograft in the amount of 2 to 3 amalgam carriers is delivered for sinus lift (Fig.1,2 white *), followed by implant placement (4.5x10 mm, >55 Ncm).  More allograft is placed before and after abutment insertion (black *).

Sinus lift with Regular Drills Last Next Xin Wei, DDS, PhD, MS 1st edition 02/07/2019, last revision 02/07/2019