A multi-unit abutment (MUA) is an abutment most commonly used with dental implants in "All-on-Four" protocols. [1] [2] They are designed for screw-retained group restorations, [3] which are often used in combination with angled dental implants [4] and whole arch replacements, as well as screw fixation of bridges made of zirconium or metal-ceramic group restorations to the implant. [5] [6] [7] [8]
Multi-unit abutments are used to align the prosthesis on a level restorative platform, adjust for variations in implant heights, and place the implant connection at the same level as or just below the gingival surface.