Implant Redo with Existing Guide M

Three months post #14 implant removal and bone graft, the existing guide is reused, but no stop fixture mount cannot be inserted into #13 implant as an anchor.  After 3.5x7.3 mm drill with 12 mm offset, the bottom of the osteotomy is not so hard; therefore sinus lift is conducted with allograft and 4x10 mm dummy implant (Fig.1).  The lifted sinus floor is in fact not noted during the surgery (Fig.1 dashed red line).  Sinus lift continues with bone graft and 4.5x10 mm (Fig.2); bone graft is squeezed out (*).  The final implant (5x8.5 mm) is not seated until use of 4.5x7.3 and 4.0x10 mm drills (Fig.3).  The implant is further placed free hand until subcrestal distal; since the torque is not high, a healing screw (S) is placed with packing allograft around the plateau of the implant  (*).  By placing a 4.5x4.5(4) mm cemented abutment at #13, a provisional is fabricated with extension to cover the bone graft at #14.  When the provisional dislodges 1.5 months postop, #14 wound does not heal with the erythematous gingiva and exposed healing screw (Fig.5).  Diabetes is not well controlled (HbA1c >6% (normal 4-5.6%)).   Poor oral hygiene is another contributing factor in failure.  After cleaning and torque 30 Ncm of the abutment at #13, impression is taken.  In fact the tooth #12 has lost the palatal cusp (Fig.6 <); a crown will be fabricated at #12 when the implant at #14 osteointegrates.  The implant at #14 is uncovered 5 months postop (Fig.7 (6.8x3 mm healing abutment)).  The implants of #13 and 14 are close to each other, which is related to the slanted ridge at #13 (^).  The osteotomy and the implant slide distal during placement (arrow).  The implant in the slanted ridge should be intentionally placed mesial to compensate for the shifting.  Or the ridge should be trimmed precisely; open surgery is necessary.  A 5.2x5.5(4) mm cemented abutment is apparently completely seated with 35 Ncm torque 6 months postop (Fig.8).   Although the distal plateau of the implant is exposed when the provisional is removed, post cementation bitewing shows equicrestal placement distal (Fig.9). 

Return to Upper Molar Immediate Implant Trajectory II 矫正，糖尿病，种植水平

Xin Wei, DDS, PhD, MS 1st edition 12/17/2019, last revision 12/06/2020