Questionable Rescue Screw Implant

Three months post cementation, the implant at #14 is found loose (Fig.1: 6.5x11 mm) and removed.  After removal of minimal granulation tissue, normal saline disappears into the apical end of osteotomy.  In fact there is no bone apically, although the sinus membrane is intact.  After try in of various taps (tapered and cylindrical, bone- and tissue-level), a 8x14 mm dummy implant is placed (Fig.2), followed by Osteogen plug and the same sized definitive implant, which has to be placed deeper to obtain ~ 45 Ncm (Fig.3).  There is minimal thread engagement.  If the implant fails, place 2 layers of PRF membrane apically, bone graft and 1 layer of PRF coronally for ridge preservation.  A healing abutment will be placed to expose the coronal end of the implant ~ 4 months postop.  The tissue-level implant remains subgingival 4.5 months postop (Fig.4).  A 8 mm healing cuff cannot be placed even after laser gingivectomy.  The implant is 2 mm subcrestal mesially.  Torque wrench cannot reverse the implant at 60 Ncm.  The implant is later reversed with Tatum wrench until it is turned with the torque wrench at 30 Ncm.  The implant remains stable, while the healing cuff with Triple Antibiotic Ointment is placed.  The healing cuff is stable 2 weeks later (Fig.5 C).  With progressive loading for a month, a crown is cemented 9 months postop.  There appears no bone loss 2.5 months post cementation (11 months postop, Fig.6).  Return to Upper Molar Immediate Implant, Armaments, IBS #3 Xin Wei, DDS, PhD, MS 1st edition 04/30/2018, last revision 04/14/2019