A Novel Technique for Immediate Loading Single Root Form Implants With an Interim CAD/CAM Milled Screw-Retained Crown
A technique is described where an interim abutment and crown are fabricated in the laboratory by utilizing computer-aided design/computer-aided manufacturing (CAD/CAM) technology and placed the day of dental implant surgery. The design and contours of the interim crown are designed by the computer software to be identical to the contours of the tentatively designed definitive prosthesis. The interim crown satisfies esthetics immediately after dental implant surgery while allowing the tissue to heal and obtain contours similar to the contours of the definitive prosthesis. The interim crown can be either cement retained or screw retained. The presented technique describes fabrication of a screw-retentive interim crown. After osseointegration is confirmed, a definitive impression is made with a CAD/CAM impression coping. The definitive prosthesis is then fabricated.

Figure 1. Preoperative view. Figure 2. Bone sounding technique by utilizing an endodontic file. Figure 3. (a) Interim abutment and crown are designed. The design is stored in the software and the definitive crown will be designed with identical contours. (b) A computer-aided design/computer-aided manufacturing interim polymethyl methacrylate abutment and crown are being milled.

Figure 4. (a) Custom impression coping is designed to have identical contours with the interim abutment/crown and the definitive crown as well. (b) A computer-aided design/computer-aided manufacturing (CAD/CAM) impression coping is being milled. Figure 5. Intraoral evaluation of the CAD/CAM interim abutment.

Figure 6. (a) After curing and removing the excess composite resin cement, an occlusal screw-retentive interim computer-aided design/computer-aided manufacturing prosthesis is completed. (b) Intaglio surface; notice the seal and lack of voids between the interim abutment and crown. The contours have been digitally designed to simulate the contours of the definitive prosthesis. Figure 7. (a) Interim screw-retained prosthesis insertion. (b) Interim screw-retained prosthesis after suturing. Figure 8. (a) Four months postoperative evaluation. (b) Intraoral view, 4 months after implant surgery. Notice the soft tissue contouring simulating the contours of the interim prosthesis.

Figure 9. Digital design of the definitive crown. The contours of the definitive restoration are identical with the contours of the interim prosthesis. Figure 10. (a) A screw-retentive definitive prosthesis is being made. The contours of the prosthesis are identical to those of the interim restoration. (b) Intraoral view with the definitive prosthesis, 18 months after insertion.
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