The 2-Visit CAD-CAM Implant-Retained Overdenture: A Clinical Report
Recently, computer-aided technology has become commercially available in the United States for fabrication of complete dentures. Manufacturers offering this technology require exclusive clinical and laboratory protocols that sharply contrast with the traditional paradigms of complete denture therapy. These protocols allow fabrication of complete dentures in only 2 clinical appointments. Currently, there are no clinical reports in the scientific literature describing the use of this technology for overdentures. This article describes the successful use of computer aided design-computer aided machining (CAD-CAM) technology for prosthodontic phase of fabrication of a mandibular implant-retained overdenture in only 2 clinical appointments. A discussion of the techniques, rationale, indications, advantages, and disadvantages of using CAD-CAM technology for complete dentures and overdentures are described in this article.
Figure 1. Occlusal view of mandible showing 2 implants (healing abutments removed) that were placed in the anterior mandible for fabrication of an implant-retained overdenture. Figure 2. Image showing the mandibular thermoplastic tray that had the handle removed and a new customized handle made from acrylic resin to facilitate proper border molding procedure. Figure 3. Image of the maxillary final impression made using light body silicone impression material. Figure 4. Image of the mandibular final impression made using light body silicone impression material. Figure 5. Image showing the anatomic measuring device (AMD) in place, after determination of occlusal vertical dimension and centric relation. The blue pin from the palate is resting on the dimple marked on the mandibular plate. Also note the maxillary incisal edge position and midline marked on the lip support component of the AMD. Figure 6. Registration of the centric relation position after placement of the clear template in alignment with the marked midline and incisal edge position. Figure 7. Frontal view of the digital teeth arrangement on the digitally articulated maxillary and mandibular virtual models presented to the clinician for approval. Figure 8. Lateral view of the digital teeth arrangement on the digitally articulated maxillary and mandibular virtual models presented to the clinician for approval.
Figure 9. Frontal view of the digital teeth arrangement with gingival simulation before final uploading to the CAD machine. Figure 10. Intaglio surface of maxillary denture with pressure indicating paste showing excellent adaptation with underlying tissues immediately after the first insertion attempt (before any adjustments were made). Figure 11. Intaglio surface of mandibular denture with pressure indicating paste showing excellent adaptation with underlying tissues immediately after the first insertion attempt (before any adjustments were made). Figure 12. Imaging showing the placement of metal housings on the torqued Locator abutments. Notice the grooves created on the metal housing to aid in mechanical retention of the resin for attachment. Figure 13. Imaging showing relief holes drilled to accommodate the abutments and the metal housings for attachment to the implants. Also note the occlusal markings after clinical remount procedure. Figure 14. Intaglio surface of mandibular overdenture after incorporation of attachments and placement of the nylon patrices into the metal housings. Figure 15. Posttreatment front view of the CAD-CAM dentures in occlusion. Note slight midline discrepancy compared to the digital preview images of Figures 7 and 9. Figure 16. Close-up view of the patient's smile with CAD-CAM dentures in place.
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