The first step was to obtain a CBCT scan of the maxillary arch, which revealed periapical pathology in teeth #12-22 (Figs. 2 & 3). In addition, tooth #21 showed significant buccal bone loss and a small piece of amalgam was located in the bone near tooth #21. After thorough analysis of the radiographic findings, a treatment plan was established to extract teeth #12-22 and maintain the ridge to reduce bone loss at the extraction sites.
As is standard protocol in my dental practice, we captured a digital impression of the maxillary and mandibular arches with the DEXIS IS 3800 intraoral scanner (Fig. 4a–c), along with intraoral photographs to document the initial oral condition. These digital models were used to fabricate the temporary removable prosthesis.
Fig. 7: CBCT scan of the anterior region of the maxilla after the extractions.
With the insurance company’s approval of the proposed treatment plan, all four teeth were extracted. After the extractions, the extraction sockets were thoroughly cleaned with EthOss degranulation burs and filled with EthOss grafting material to promote primary wound closure and healing (Fig. 5).
To preserve both aesthetic and functional aspects for the patient during the interval between tooth extraction and the new bridge, a temporary removable prosthesis was fabricated (Fig. 6). The patient’s general dentist has also been working fully digitally for years, and the temporary prosthesis was made from a digital impression and printed models.
Two months after the extractions, we obtained a CBCT scan of the maxilla (Fig. 7) and recorded digital impressions using the DEXIS IS 3800 intraoral scanner (Fig. 8). These scans were necessary to begin the implant planning process and create the surgical guide.
:sharpen(level=0):output(format=webp)/up/dt/2024/03/A-fully-guided-digital-workflow-for-predictable-implant-planning-and-placement_Fig.9_Figure-8_implant-planning-in-all-four-positions.png "Fig. 9: Implant design for all four positions.")
Fig. 9: Implant design for all four positions.
During the implant design phase, we created a preliminary design using 3D imaging software with a prosthetic approach to implant design (Figs 9 & 10) and the design was exported to a surgical guide design software for the final design and fabrication of the surgical drill guide (Fig 11a –c). The implants were designed in all four positions with the objective of identifying the two most optimal and accessible positions for the placement of two implants and corresponding bridge restoration.
After completion of the perforation design and reconstruction, the surgical guide was 3D printed with a Stratasys printer using MED610 resin (Stratasys). The two implants (4.1 × 12.0 mm Straumann Bone Level Tapered, Regular CrossFit, SLActive, Roxolid) were then placed using the Straumann surgical guide for precise guidance. The remaining piece of amalgam on the bone of tooth #21 was carefully removed—only a small piece on the gingiva remained (Fig. 12). The buccal bone was re-thickened with EthOss and the wound was closed with a semi-submerged technique, facilitating proper healing and integration of the implants (Fig. 13a & b).
After a ten-week osseointegration and healing period, the patient returned for a final assessment of implant stability using the implant stability quotient measurement.
The next step will involve the completion of the final denture, which will be performed by the patient’s general dentist. To create the screw-mounted monolithic bridge, a digital impression will be taken using an intraoral scanner, and the dental technician will also work completely digitally – as far as possible – on the final prosthesis.
