Guided Flapless Surgery With Immediate Loading for the High Narrow Ridge Without Grafting
Computer guided implant treatment allows implants and associated restorations to be precisely placed during the same procedure directly through the gingiva with reduced postoperative complications and surgical time. When bone height is adequate but very narrow, the virtual guided sleeve is often placed too deeply into the ridge crest interfering with the seating of the surgical template. This case report of a patient exhibiting very narrow residual ridges due to severe resorption describes a new computer guided procedure using a single surgical template maintaining bone height and immediate restoration without a mucoperiosteal flap. The success of this technique is the result of innovative modifications in the software as well as instrumentation. Modifications include planning a different implant length virtually to raise the position of guide sleeves, alteration of drilling sequences, modifications of the start drill, incorporation of osteotomes, and use of an alternative implant seating mount. The combination of these methods allows for deeper site preparation and implant seating beyond the default settings, without any crestal bone reduction. These modifications not only make the guided concept possible for the entire preparation and seating procedures, but also allow for the slight removal of bone that would interfere with the implant seating through the surgical template without a mucoperiosteal flap. This new approach to computer guided surgery maintains prosthetic precision in the fabrication of a provisional restoration prior to implantation with minimal delivery adjustments using prefabricated conical abutments when placing implants at differing levels into the high narrow ridge.
and 2. Figure 1. (a) Preoperative view of the maxillary edentulous arch. (b) Screen capture of 3-dimensional preoperative residual ridge. (c) Cross-section demonstrating very high narrow ridge. Figure 2. The virtual guided sleeve interferes with the ridge crest and will not allow seating of the surgical template.
and 4. Figure 3. Sequence of planning the implant in the compromised sites. (a) The position of the desired implant (7 mm). (b) Increase of the planned implant length from 7 mm to 10 mm. (c) Coronal movement of the new 10-mm implant by 3 mm, clearing interference between the guided sleeve and bone. Figure 4. The first 6 implants anterior and posterior to the compromised sites.
and 6. Figure 5. The implants placed in the compromised sites. Figure 6. (a) Modification of the 1.5-mm diameter drill (anchor pin drill). (b) Fabrication of the drill guide for 1.5-mm diameter drill ready for insertion into the surgical template.
Figure 7. Modification of the start drill by removal of the stop. Standard start drill (top), Modified start drill (bottom) with arrows indicating depth-limiting stop. Figure 8. Use of osteotomes in a guided fashion through the surgical template. Figure 9. Implant mounts. Guided implant mount (left) and original single-tooth implant mount (right).
and 11. Figure 10. (a) Immediate placement of implants with multiunit abutments to within 1 mm of the soft-tissue crest. (b) Immediately placed maxillary fixed provisional prosthesis opposing mandibular fixed implant prosthesis demonstrating full maintenance of bone height. Figure 11. Radiographs taken after prosthesis insertion and demonstrating precise fit of cylinders to abutments.
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