Abstract: The parts and components can be manufacturing by computer aided design and manufacturing (CAD/CAM) and machined with very accuracy using a computer with joined software linked to a milling machine. CAD/CAM technology manufactures prosthesis from the data obtained from the patient's mouth. The aim of the current research is to fabricating crowns and bridge made of different brands of Yttria stabilized Tetragonal Zirconia Polycrystals (3-5 mol% Y-TZP) and employed different cutting speed by Computer Aided Design and Manufacturing Techniques (CAD/CAM). The experimental work involved the fabricating of crowns only from Yttria stabilized tetragonal zirconia polycrystals (dental direct block) and bridges made from three different brands of Yttria stabilized Tetragonal zirconia polycrystal (Kerox dental block, dental direct block and VITA YZ HT block) by computer aided design and manufacturing techniques and studying the effect the cutting speed on the surface properties and mechanical properties of zirconia such as flexural strength and microhardnes. Other characteristic techniques have been performed such as XRD and SEM to characterization of zirconia. It is found from the results of X-ray diffraction patterns carried out on presintered zirconia blocks the predominant phase is Tetragonal (T) and the appearance of the monolithic phase at some the peaks but after milling and sintering only Tetragonal phase (T) was identified for all of the samples except in Kerox dental block the monolithic phase was appear at 150 m/min cutting speed. The results scanning electron microscope of the surface morphology for each brands reveals milling traces and scratching induced by the milling tool also crack and microchips and pores appeared on the surface machining due to densification process. The results of mechanical tests were found flexural and hardness decrease with increasing cutting speed.