Objectives: The purpose of this study was to compare the internal and marginal fit of metal cores for metal ceramic crowns fabricated using three different construction techniques. Materials and methods: Upper full arch Giroform model with missing 4 incisors, first molars, and right second premolar was prepared to receive 5 full arch metal frameworks constructed by each technique; traditional Casting, CAD/CAM milling, and Selective Laser Sintering (SLS). Internal gap of the retainer was performed by replica technique, using light and heavy body addition silicon for marginal and internal gap measurements. Six sections at each tooth were cut to measure the gab distance at the: Margin, Axial, Axio-occlusal angle, and Occlusal area. All measurements were performed using compact stereo microscope under 100 magnification. Data was collected and statistically analysed. Results: Marginal gap showed statistically significant difference between three tested techniques; it was found to be least for core fabricated with SLS technique, followed by CAD/CAM, and the widest gap was found at cores fabricated with Cast technique . The least internal gap distance was found to be at the axial surface, followed by the axial occlusal line angle, and the widest internal gap distance was found to be at the occlusal surface. Conclusion: Metal ceramic full arch rehabilitation fabricated with SLS, CAD/CAM, and casting systems exhibited clinical marginal adaptation within an acceptable range.