Hard Bone: No Expansion

With 9 mm offset, the cylinder portion of the 2.2x8.5 mm drill does not engage to the metal sleeve of the guide at #28 after pointed drill (Fig.1).  This issue could be solved with 12 mm offset, although it has no ill effect in this case.  Fig.2 shows the site of #28 immediately before bone expansion and after use of 2.2x11.5 mm drill and small-scaled ridge split (^).  The bone is so hard that the bone expansion is minimal (Fig.5) with autogenous bone graft and implant placement (Fig.4).  There is the bone buccal to the implant clinically.  A 5x10 mm implant is placed at #31 in the same appointment (Fig.3).  Because of inability to masticate on the left (#18 root fracture with infection), the patient wants to restore #28 and 31 implants 3 months postop (Fig.6,7).  The implant at #28 is removed while the healing abutment is being un-torqued without noting bone loss mesially (Fig.7 * (next similar case)).  Bone graft is placed (Fig.8 (*),9).  Pay attention radiolucency next the apex of the neighboring tooth (Fig.9 ?)  before re-placement of an implant.  The patient is upset, since he cannot eat.  Two weeks later, a 6.5x4(4) mm cemented abutment is placed with 25 Ncm at #31 with a provisional for progressive loading for 2 weeks.  Impression is taken.  Two weeks later, a permanent crown is cemented without removing the underlying abutment.  Two days later, the crown/abutment dislodges; a 6.8x6 mm healing abutment is placed.  Eight days, it is difficult to reseat the existing crown and abutment.  The mesiodistal edentulous space is limited as well.  A 5.2x4(4) mm cemented abutment is able to be seated and torqued (30 Ncm) smoothly; in fact the clearance from the crestal bone (Fig.10 *) is not ample.  If the abutment screw becomes loose in function, a profile drill should be used or a 4.5 mm in diameter abutment be placed.  The abutment seems to remain in place immediate post cementation (Fig.11).  Implant failure is probably due to no socket preservation (buccal plate atrophy) and too early restoration.

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Xin Wei, DDS, PhD, MS 1st edition 07/29/2019, last revision 05/23/2020