Shorter Implant is In Demand
Mr. Shi is in his late fifties and has severe periodontal disease, compounded by occlusal trauma. He has lost several of the upper teeth, whereas the teeth are intact (dentulous). Fig.1 is a CBCT sagittal view, showing missing teeth #13 and 14. The adjacent teeth #12 and 15 have sign of bone loss and infection (#15). Fig.2 is a coronal section through #14 ridge. The bone height is 3.4 mm.
The general treatment plan is to place implants as many as possible. The tooth #15 was an abutment tooth for the upper removable partial denture (RPD). The mobile tooth has been extracted. Immediate implant was placed with simultaneous sinus lift without grafting (Fig.3-5, 1,2,3). After osteointegration, a provisional crown is placed (Fig.5). The existing RPD is stable. Then an implant is placed at the site of #13 with bone expansion technique. Both implant surgery procedures reveal dense bone. There is no postop complication.
When 4.5x11 mm tap was inserted at the site of #14 a month ago, it was solid (Fig.3T). Primary stability was achieved (>60 Ncm) with insertion of a 5x11 mm tissue-level implant (Fig.4). Autogenous bone (although limited amount) was saved from osteotomy with slow-speed reamers and pushed back to the osteotomy site before implant placement. No additional grafting was done. Eight out of 11 mm of the implant has rough surface (to be osteointegrated), although the thread portion is 6 mm long. There is postop nasal hemorrhage. Fig. 5 was taken 11 days postop.
If a bone-level implant with 6 mm long or tissue-level implant with 8 mm long were placed in this case, approximately 2 or 3 mm less of the implant would be sticking into the sinus with less chance of sinus membrane perforation. In addition, the wound could be closed primarily with less chance of postop infection from the oral side with a bone-level implant. The implant at #14 appears not to be nude in the sinus (4 years 4 months post cementation, Fig.6 (CBCT)).
3 8/9 10 15 19 30 Xin Wei, DDS, PhD, MS 1st edition 11/17/2013, last revision 10/01/2018