Background: Different digital fabrication techniques affect the marginal adaptation of tooth supported provisional and final dental prosthesis. However, there is minimal scientific evidence which technique will be effective for producing tooth supported provisional dental prosthesis with predictable marginal fit. Aim of the study: to evaluate the effect of the two CAM fabrication techniques; milling versus 3D printing on the marginal fit of tooth supported restorations. Materials and methods: two abutment teeth of a modified typodont with a missing left mandibular first molar were prepared to receive a ceramic FDP. A master reference stone model was then, constructed. An optical impression (STL file) of the reference model was taken. A provisional tooth supported FDP was designed on the CAD software using the STL file of the reference model. Eight Restorations were fabricated by different CAM techniques. The restorations were divided into two groups according to the fabrication method; group A (milled restorations) (n=4) and group B (3D printed restorations) (n=4). Finally, the marginal fit of the provisional dental prosthesis was assessed by a stereo optical microscope on the stone reference model.  Mann-Whitney U test was used to compare between the two groups. The significance level was set at P ≤ 0.05. Results: the results showed that there was no statistically significant difference between the vertical marginal gap values of the two tested groups. Conclusion: The vertical marginal gap values of provisional restorations fabricated by the two tested methods of manufacturing were comparable and within the acceptable range of 120 µ.