A 58-year-old man was referred by his general dentist for replacement of a failing fixed bridge from teeth Nos. 7 through 10. Both abutment teeth showed decay, and radiographically, tooth No. 10 had an apical radiolucency and widened periodontal ligament space. The treatment plan comprised removal of the abutment teeth and restoration with individual implant-supported fixed prostheses for each missing tooth. His existing provisional prosthesis was used to determine the optimal position and orientation of the implant fixtures. A GALILEOS cone-beam computed tomography (CBCT) (Dentsply Sirona, www.dentsplysirona.com) scan demonstrated adequate bone height; however, deficient crestal bone width in the sites necessitated prosthetically based implant placement. After determining radiographically that the basal bone was sufficient to achieve initial primary stability, it was planned to surgically expand the ridge width simultaneously with removal of the failing teeth and placement of four dental implants.
Key Takeaways
• Ideal implant positioning, angulation, and depth were determined by merging CAD/CAM and CBCT data and following the concepts of prosthetically driven implant planning.
• A GALILEOS implant surgical plan was used to design the guided surgery protocol used for osteotomy preparation and implant placement, specifying drill guides, lengths, and diameters, implant drivers, and depth positions to enable exact replication of the surgical plan in the patient.
• GALILEOS guided implant surgery facilitated extremely accurate implant placement into the expanded ridge.
About the Authors
Jay B. Reznick, DMD, MD
Director
Southern California Center for Oral and Facial Surgery
Tarzana, California
Diplomate, American Board of Oral and Maxillofacial Surgery
Figure 1
Fig 1. The patient presented with a failing bridge from teeth Nos. 7 through 10. Tooth No. 10 had a significant periapical radiolucency and periodontal ligament space widening around most of the root.
Figure 2
Fig 2. A GALILEOS CBCT scan was obtained to evaluate the dental pathology and bony architecture. Scanning was performed using a special bite plate with multiple radiopaque fiducial markers, with Futar® Scan (Kettenbach) used as bite-index material. This bite plate would be converted into the surgical guide by SICAT, a Sirona company.
Figure 3
Fig 3. A CEREC Omnicam was used to obtain an optical impression of the patient’s maxillary dental arch. These data were merged with the GALILEOS CBCT image to plan the dental implant position and orientation based on the final prosthesis.
Figure 4
Fig 4. Following the concepts of prosthetically driven implant planning, the ideal position, angulation, and depth of each implant fixture were determined by merging CAD/CAM STL and CBCT DICOM files.
Figure 5
Fig 5. The GALILEOS planning report indicated that sufficient alveolar ridge height existed for 15-mm-long implants. However, a deficiency in the required 2 mm of buccal and palatal bone surrounding the implant fixtures when placed in the ideal positions prompted the treatment plan to include alveolar ridge splitting to both the buccal and palatal to achieve sufficient bone thickness around each implant.
Figure 6
Fig 6. The guided surgical template contained master sleeves of specified diameters and positions that would control the location, angulation, and depth of each osteotomy drill and implant fixture. In this case, the surgical guide was produced by SICAT from the indexed scan plate (seen in Figure 2). This allowed the surgical plan in the GALILEOS implant software to be translated to the surgical procedure.
Figure 7
Fig 7. After surgical access to the alveolar ridge was accomplished, teeth Nos. 7 and 10 were removed. Then, using a Piezosurgery saw, an osteotomy, approximately 15 mm in depth, was made across the surgical site.
Figure 8
Fig 8. Next, using a series of bone-expanding osteotomes, the alveolar ridge from teeth Nos. 7 through 10 was expanded to move the cortical bone such that 2 mm of bone would be on the facial and palatal aspects of each implant fixture placed.
Figure 9
Fig 9. The implant fixtures were then placed using the SICAT surgical guide. The implant drivers are designed to release atraumatically from the implants without disturbing their positions. This is especially important where the ridge has been expanded or in the case of immediate implant placement into extraction sites.
Figure 10
Fig 10. After removal of the surgical guide, the integrity of the bone on the facial and palatal was verified. Then, particulate freeze-dried bone was placed into the voids in the osteotomy and around the implant fixtures to enhance healing and implant stability.
Figure 11
Fig 11. A resorbable collagen barrier membrane was placed over the grafted ridge. The soft tissue was mobilized to facilitate tension-free primary closure over the expanded ridge containing the implants. Polytetrafluoroethyene monofilament sutures remained for 2 weeks after surgery.
Figure 12
Fig 12. Panoramic reconstruction view of the postoperative CBCT scan image showed four ideally spaced, parallel dental implants at the crest of the expanded alveolar ridge.
Figure 13
Fig 13. Cross-sectional views of the CBCT demonstrated that the dental implants were placed into the planned positions, with the fixture apex in stable alveolar ridge and the cortical expansion provided by the ridge-split osteotomy providing adequate bone thickness both facial and palatal to the implants.
Figure 14
Fig 14. After allowing 4 months for healing of the bone graft and osseointegration of the four implant fixtures, the surgical site was re-entered using a serpentine crestal incision. The ridge had fully healed, and healthy bone was covering the implants and in the osteotomy space.
Figure 15
Fig 15. Two weeks after implant uncovering, healthy keratinized tissue surrounded the healing abutments. The patient was then referred to his general dentist for prosthetic restoration of the four dental implants.
Figure 16
Fig 16. Periapical radiographs taken approximately 2 months after placement of the final prostheses showed excellent maintenance of bone level surrounding all four implant fixtures.
Figure 17
Fig 17. Two months after placement of the final restorations, a wide band of keratinized gingival tissue was evident adjacent to the implant-supported prostheses. In the interproximal spaces, the contour of the crowns facilitated migration of keratinized tissue to form interdental papillae.