Case Report on Digital Workflow
The use of cone-beam computed tomography (CBCT), digital scanners, and computer aided design/computer aided manufacturing (CAD/CAM) has revolutionized implant dentistry. The following clinical report demonstrates the digital workflow using CBCT imaging, combined with virtual treatment planning involving three-dimensional (3D) model scanning and CAD/CAM technology for implant placement.
A healthy 55-year-old man with partially edentulous dentition presented for implant restoration of his missing maxillary and mandibular teeth. The patient wanted a fixed interim prosthesis inserted immediately after implant placement. Five implants were planned. A digital implant planning workflow for a fully guided surgical protocol was used. The patient’s final impression of the mandibular arch would be used for immediate fixed denture fabrication.
Cone-beam imaging was performed to acquire the preoperative anatomic information. The digital imaging and communications in medicine (DICOM) files generated from the CBCT, along with both mandibular casts were sent to the lab. Prior to initiating digital planning, three 3D model scans were performed: preoperative definitive cast, tentative ground cast without wax-up, and the tentative ground cast with wax-up. This process established a clear soft tissue outline that could be viewed from the axial, coronal, and sagittal planes. Based on the virtual dental casts and DICOM data, the implant positions were planned for the mandibular interforaminal area.
Upon finalizing the implant positions, two surgical guides were fabricated using CAD/CAM technology. The bone reduction template was designed to be fitted on the alveolar ridge on both sides by extending the flanges distally to improve stability. The window created over the extraction sockets served as a vertical bone reduction reference plane. The implant placement template possessed two identical distally extended flanges to provide stability.
On the day of surgery, all of the remaining mandibular teeth were extracted and a full thickness mucoperiosteal flap was reflected to accommodate the bone reduction template. The alveolar crest was reduced until the bone level was flush with the window of the bone reduction template. The second implant placement template was seated on the reduced ridge to provide guidance for osteotomy preparation. Five tissue-level implants were placed in the planned positions. After implant placement, all remaining jumping distance within the sockets were grafted with xenograft bone particulate.
The interim prosthesis was gently inserted and it was confirmed that no interference or unfavorable contact existed between the interim prosthesis, temporary abutments, and opposing dentition. The interim prosthesis was picked up intraorally using self-curing attachment pickup resin. The occlusal contacts were adjusted and verified for even distribution in centric relation. Group function and elimination of premature contact were achieved in eccentric movement with multiple contacts between the maxillary teeth and mandibular interim prosthesis on the working side.
The patient was satisfied with the outcome of the immediately inserted interim prosthesis (Figures 1A-1D). Throughout therapy, the use of CBCT, 3D model scanning, and CAD/CAM aided diagnosis, case planning, and treatment.
From Decisions in Dentistry. August/September 2024; 10(5):46
