Introduction: The demands for constructing a passively fitting immediate full arch screw retained restoration are rapidly increasing; intra-oral spot welding has been a well-documented idyllic modality for a long time. New variations were proposed to overcome welding limitations, one recent alternatives is the introduction of Fast Bridge, Fast Pack system by iRES.

Aim of the study: To evaluate the marginal vertical gap between abutment finish-lines and framework respective surfaces using optical microscope.

Materials and Methods: This In-vitro study involved two models with four implants installed in each numbered from #1 to #4 representing the study groups, group A and B. With a total number of 16 samples, eight screw-retained frameworks were constructed on each model.
For Group A: Using the conventional intra-oral spot welding technology, as For Group B: Using the iRES bars.
Applying one screw test method, with the help of high accuracy industrial optical microscope, a passivity analysis was done, By measuring the marginal vertical gap for each implant at three points ( mesiobuccal, midbuccal and distobuccal ).

Results: The study has shown that there was a statistically significant difference between the two techniques (p < 0.001).

Conclusion: Within the limitations of this study, it can be concluded that the evaluated technique in this study renders more passive frameworks. It displayed absolute fit results that were only theoretically desired. Elimination of tension at construction phase played a key role in the final framework fit.