Four NiCr dies were prepared and duplicated to resin stone dies, Different CAD/CAM systems were used to fabricate zirconium cores in this study, Bite checker and fit checker was used to measure the marginal and internal adaptation of the fabricated zirconia cores, On comparing means of marginal and internal gaps of the whole selected points(marginal, rounded shoulder, axial and occlusal) Hint-els CAD/CAM produced lowest gaps.