Trephine Core: An Alternative Sinus Lift Technique

Figure 1. Trephine drill used to create the majority of the implant osteotomy. Figure 2. Surgical sequence for use of the trephine to gain ridge height in the maxilla. Figure 3. Trephine diameter in comparison with the implant that will be placed into the osteotomy created by the trephine demonstrating the osteotomy matches the core diameter of the implant while allowing the implant threads to engage into the bone when placed. Figure 4. Initial radiograph demonstrating root resorption of the overretained deciduous molar. Figure 5. Radiograph after extraction of the overretained deciduous tooth. Figure 6. A 5.0 × 10.5-mm threaded fixture (Biohorizons) with an internal hex connector was selected to fit the intended site.

Figure 7. After a full thickness flap, the trephine is used to start the osteotomy. Figure 8. Radiograph after initial penetration of the trephine into the site to verify the trajectory of the intended osteotomy. Figure 9. Osseous core created by the trephine. Figure 10. An osteotome matching the outer diameter of the trephine is used to finalize the osteotomy created by the trephine after removal of the osseous core. Figure 11. Radiograph taken with the osteotome in the site to verify the trajectory of the osteotomy and its relation to anatomic structures. Figure 12. Implant has been placed into the site created with the trephine, and placement head/stock abutment head is shown still attached to the implant. Figure 13. Radiograph at implant placement with placement head on fixture. Figure 14. After 5 months of healing, the patient presented to initiate the restorative phase. The site shows an absence of inflammation and the cover screw can be visualized.

Figure 15. A rotary tissue punch is used to expose the cover screw in preparation to initiate the restorative phase. Figure 16. The rotary tissue punch has created a core of soft tissue in the ideal location on the ridge over the integrated implant. Figure 17. Radiograph of the healing abutment placed on the implant, demonstrating integration of the fixture and an adequate sinus elevation with the infractured core. Figure 18. A healing abutment was placed, and tissue was allowed to mature and heal after exposure of the implant before restoration of the implant. Figure 19. Two weeks after removal of the soft tissue core created by the tissue punch, the healing abutment was removed and the implant connector can be visualized. Figure 20. Cone beam computerized tomography cross-sectional view through center of the implant after 5 years of function, demonstrating stable bone levels at the apical, buccal, and lingual margins. Figure 21. Clinical photograph taken 5 years postimplant placement and restoration, demonstrating stable peri-implant soft tissue. Figure 22. Radiograph 5 years postimplant placement and restoration, demonstrating stable bone levels with no bone loss.