The “All On 4” concept is a term coined by Nobel Biocare to describe the replacement of an entire arch of teeth with an implant supported fixed bridge which is supported by only four implants. This can be done for both the upper and lower arch. Due to the difference in bone quality, the upper arch often requires six implants rather than only 4. The treatment process starts with 3D computer based planning using digital imaging and cone beam CT scan information to plan precisely where the implants are to be placed in the jaw to best support the fixed bridge. This planning makes for quicker surgical times and a final result which is more predictable. Impressions for a provisional fixed bridge are taken at the time of surgery and the bridge is fitted within 3 days. This bridge is best viewed as a 6-12 month “healing bridge” which should then be replaced with a stronger final prosthesis following this healing period. There are a few options for the material choice of the final fixed bridge. Generally the choice for the final bridge is between having a fixed acrylic tooth bridge or a porcelain tooth bridge. Both bridges (acrylic or porcelain) are made with an internal CAD/CAM single-piece milled titanium support framework. This is the most accurate and strongest method for making full arch fixed bridges for the “All On Four” system.