After implant removal, a 4.5x11.5 mm drill is used, but it cannot reach the depth due to high bone density.  800 RPM instead of 50 RPM may help.  When the implant is reseated, it appears to be .5 mm deeper than before clinically, although it looks incompletely seated in X-ray (Fig.4 <).  The insertion torque is 60 Ncm.  Allograft mixed with PRF is placed around the implant with cover screw, particularly mesiolinguodistal (Fig.4 *). The majority of the bone graft is lost without immediate provisional in 4 months (Fig.9 * (<: socket shield)).  Then a 5.5x5 mm healing abutment is inserted for impression next appointment.  A 5.2x4.5(4) mm cemented abutment is placed before impression (Fig.10).  PET Last Next  Xin Wei, DDS, PhD, MS 1st edition 03/12/2020, last revision 03/15/2020