Vertical microgap and passivity of fit of three-unit implant-supported frameworks fabricated using different techniques.

Purpose: This study compared the vertical microgaps of milled zirconia and cobalt-chromium (Co-Cr) implant-supported fixed dental prosthesis frameworks to those seen in one-piece frameworks cast with different techniques.

Materials And Methods: Two threaded implants were used to simulate the rehabilitation of a maxillary partially edentulous space from the second premolar to the second molar. Three-unit screw-retained prosthetic frameworks were fabricated and divided into the following groups (n = 10 in each group): 1 = cast in Co-Cr using burnout cylinders; 2 = cast in Co-Cr using cast-on Co-Cr cylinders; 3 = one-piece cast in Co-Cr using a passive fitting technique; 4 = milled Co-Cr framework; 5 = milled zirconia framework.