Tannure ALP, et al. - The changes were evaluate in the external-hexagon surface of the titanium (Ti) implant before and after mechanical cycling, when coupled with zirconia (Zr) abutments (A) manufactured by three computer-aided design/computer-aided manufacturing (CAD/CAM) systems (Neodent Digital, Zirkonzahn, and AmannGirrbach) and the ZrTi abutment manufactured by Neodent. The Zr Neodent abutment (AZrN) group had shown more surface alterations among the Neodent abutments. AZrZ samples had given the most altered surfaces among the Zr groups, implying that alterations on the implant/Zr abutment hexagon surfaces were associated with the abutment milled hexagon shape.