Procera Implant Bridge (PIB)
Another alternative for patients is a Procera® Implant Bridge (PIB), a subset of hybrid dentures that combines the advantages of porcelain fused-to-metal restorations with those of a hybrid denture. These are full dentures supported only by implants, without contact with soft tissue, and screwed to a structure built on multiple abutments in the maxilla and mandible. Patients cannot remove the bridge themselves, so they feel more comfortable with their natural tooth, but they must also commit to regular maintenance visits every six months or once a year.
The PIB consists of a pink porcelain, zirconium, or acrylic framework that is attached to the implants, preparing each tooth individually to receive a cementable single crown. Porcelain or zirconia crowns offer patients a better esthetic outcome and increase the durability of the restoration as well as bite strength and stability. These restorations are a more expensive alternative for patients with other drawbacks such as porcelain spalling and difficult repairs for large fractures.
Implant position is less critical than with a hybrid prosthesis because it can be corrected with the framework and access for screw holes is not required. The framework can be fabricated using traditional wax and casting techniques or milled using CAD CAM technology. For the restoration to be successful, a passive fit on the implants must be ensured, as with any other implant-supported restoration. The number of implants required for this restoration depends on the number of teeth to be replaced, although five implants should be the minimum.
The framework is first fabricated in the laboratory and later completed with individual crowns made of porcelain or zirconia, which are cemented onto the framework. If one of these crowns gets chipped or fractured, it can be easily replaced without having to remake the entire restoration.
When proposing this treatment plan to patients, certain considerations must be taken into account, such as adequate interocclusal space for an appropriate prosthetic design with implants, framework, and crowns, as well as the type of antagonist tooth the patient has. Patients with an acrylic denture in the opposing jaw may experience more rapid wear of the denture, requiring more frequent replacement. Natural teeth can also be worn against a full denture made of porcelain or zirconia.
As with hybrid dentures, patients must be instructed in thorough oral hygiene, as they will not be able to remove the denture, and proper removal of plaque and debris must be ensured to ensure implant stability and prevent peri-implantitis. This treatment is not recommended for elderly patients who are unable to clean these prostheses and for whom an overdenture may be a better alternative.
