Case Presentation: Maxillary Reconstruction With a Zirconium All-on-6 Hybrid Prosthesis

Published Date 01/09/2019
For today’s edentulous patient, the zirconium hybrid prosthesis, supported by 4 to 6 dental implants, may be considered the holy grail of denture rehabilitation. The patient is afforded a fully exposed palate, exceptional durability, and lifelike appearance and function. For those dentists who haven’t placed such a restoration, you might be surprised to know that the process does not require any special skills beyond utilizing sound techniques in denture fabrication. The most important step could be the selection of a capable surgeon who possesses surgical acumen and retains close ties to the principles of restorative dentistry. Implants are planned and placed on properly prepared ridges to make their utilization seamless, as will be demonstrated in this case presentation. Finally, an exceptional dental lab familiar with the fabrication process is paramount to success.

Case in Point
Our patient, Rick, presented with a highly atrophic, disfigured maxilla as a result of advanced periodontal and occlusal disease (Figure 1). It had been addressed with full maxillary extraction and placement of an immediate denture. Little natural bone remained following exodontia. Options for a more permanent fix were discussed with Rick, who wanted a fixed, open-palate solution to his edentulism. The hybrid option was discussed, and a decision made to engage Dr. Ian C. Tingey, a Connecticut-based oral surgeon, to reconstruct Rick’s maxilla. This would be followed by placement of 4 to 6 implants.
Figure 1—Preop clinical view of atrophic maxilla
Figure 2—Postop panoramic view
Figure 3—Postop reconstruction
Fast-forward 18 months and Rick reports for duty with his maxilla rebuilt. Per Dr. Tingey, “The atrophic anterior maxillary alveolus was augmented with autogenous block bone grafts, harvested from the mandibular ramus regions bilaterally. The atrophic posterior maxillary alveolus was reconstructed via bilateral subantral augmentations utilizing particulate hydroxyapatite (BioOss).” And you will note the strategic placement of 6 NobelReplace Groovy implants (Nobel Biocare) (Figure 3). Case planning was assisted via Anatomage software and surgical guide, and visualization was enhanced with PrismPro 5.5x loupes (SurgiTel).
Figure 4—Master model generated by the transfer impression using Aquasil Ultra Cordless tray and light body impression system
Figure 5—Duralay verification jig is used to confirm accuracy of transfer impression. A passive fit points toward an accurate impression
Figure 6—Wax try-in for occlusion and esthetic evaluation
Rick was ready for the restorative portion of his treatment. The most critical step involved fabricating a master model that reproduced the actual locations of Rick’s implants. A pickup impression taken with Dentsply Sirona’s Aquasil Ultra Cordless registered the location of his implants via withdrawal of 6 Nobel Biocare transfer components (Figure 4). A verification jig was used to confirm that the original transfer impression was accurate (Figure 5). We then proceeded with the usual denture fabrication steps, complete with wax bite rim, centric relation records, and esthetic try-in (Figure 6). Upon CR verification and patient approval of esthetics, the setup was returned to York Dental Lab of Branford, CT, for fabrication of a screw-retained methyl methacrylate (MMA) replica of the planned zirconium hybrid (Figure 7). Upon return and installation of the MMA replica denture, the occlusion was fi ne-tuned and the patient released to wear and assess appliance comfort and function over a 2-month period. It was critical that all aspects be considered, including speech, the ability to maintain hygiene, and comfort in function.
Figure 7—MMA provisional to serve as the precursor to the final restoration
Figure 8—View of underside of appliance and 6 retention screws
Figure 9—Completed zirconium hybrid denture
At the end of the trial period, Rick reported that he was comfortable and ready to have his MMA provisional replaced by the zirconium hybrid. Rick’s MMA appliance was removed, healing caps replaced, and he resumed wearing his transitional full denture. Rick’s final appliance was ready in a month. During that time, his MMA appliance was digitally scanned to allow the zirconium milling of an exact replica (Figure 8). Rick was thrilled with his zirconium hybrid (Figure 9) and has managed a high level of hygiene since placement. Note: A pink composite (VOCO’s Amaris Gingiva) was used to seal the screw holes to enhance the ability to visually differentiate acrylic from zirconium. There you have it: a capsulized version of a rather complex case that really wasn’t that complex once the oral surgery was completed.
PrismPro loupes range from 5.5x to 8.0x and offer ultrasharp resolution images. Designed specifically for detailed surgery, restorations, and cosmetic procedures, these loupes act as a portable microscope.
This gingiva-shaded restoration system facilitates individual shade-matching using a combination of a base shade (nature) with 3 mixable pink opaque shades in white, light, and dark—making it ideal for Class V restorations.
Dr. Goldstein, a Fellow of the International Academy of Dento-Facial Esthetics as well as a Fellow of the Academy of General Dentistry, practices general dentistry in Wolcott, CT. Recognized as one of the Leaders in CE by Dentistry Today for the last 10 years, and for his expertise in the field of dental digital photography, he lectures and writes extensively concerning cosmetics and the integration of digital photography into the general practice. He has authored numerous articles for multiple dental periodicals both in the U.S. and abroad.
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