Abstract: The aim of this study was to theoretically evaluate whether the passivity of the fit of the cast in one-piece screw retained dental implant-supported prosthesis is feasible. A mathematical approach was used for the purposes of this study. It was proved that the distortion of the cast in one-piece screw retained dental implant prosthesis is inevitable. Any effort for the fabrication of a cast in one-piece implant screw retained superstructure with a passive fit is impracticable. This is due to the involvement of too many materials and technical factors. The summation of the small independent distortions that these factors cause cannot total to zero.