Anterior 4-Unit Fixed Implant Bridge
A healthy, 52-year-old Hispanic male presented for restoration of 2 implant fixtures at the site of teeth Nos. 7 and 10. The patient had lost the maxillary incisors in a previous automobile accident, and 2 Nobel Biocare implant fixtures had been placed. Healing was uneventful but the patient reported multiple incidents of a ?broken? acrylic provisional denture due to his bite.
The patient agreed to a treatment plan to restore the 2 implant fixtures with custom zirconium screw-retained abutments and construction of a 4-unit fixed all-zirconium bridge. To test the work flow and accuracy of ?new? digital software and milling technology, we decided to restore this case in a 100% digital environment without any models or impressions to verify the fit of the custom abutments.
After 6 months of healing, implant stability and osseous integration was confirmed with a panoramic x-ray. After removing the 5-mm healing abutments, an Osstell smartpeg was placed in each implant fixture body. The Osstell implant stability measurement device gave an ISQ=78 for each implant.
Two screw-retained Glidewell Inclusive Direct implant scan bodies for the Nobel RP implants were placed at the implant sites No. 7 and No. 10. Using the iTero digital scanner, full arch maxillary/mandibular and centric bite scans were recorded. The 3D image was automatically cleaned-up with the chairside software, and the STL files were sent to Glidewell dental laboratory to be used in the CAD/CAM process. Using a library of implant fixtures, a virtual implant fixture was placed using the CZ software. When the design process was complete, the screw-retained all-zirconium abutments were milled. Similarly, the all-zirconium ceramic 4-unit fixed bridge was designed and milled using CAD/CAM technology. Unique to this case, the custom abutments did not have a separate try-in nor were any models used for the case.
In the same delivery visit, the zirconium abutments and the completed 4-unit all-ceramic milled BruxZir bridge was trial fit and checked for occlusion. There was ?tight? anterior coupling for this case as evidenced by the history of transitional interim provisional denture fracture. The occlusion was checked and presented and no adjustment was required. The anterior view of the final prosthesis demonstrates optimal M-D width proportion, incisal edge proportion, gingival pontic/tissue contact, and excellent shade/esthetics. The soft-tissue lip position and speech phonetics appeared to be optimal. Following the trial fit, the fixed bridge was removed, the zirconium abutment retention screws ?torqued? to 35 Ncm, the abutment screws covered with a cotton/cavit and the prosthesis cemented with Fuji Cement.