Introduction: All-on-Four used with anatomical limitations in the atrophied edentulous mandible. All on four requires rigid splinting by metal bar like welding for better distribution of load around implants.The aim of this study: to evaluate the effect of splinting implants in All-on-four design using welding technique on strain induced from vertical loads on both axial & tilted implants Materials and methods: lower completely edentulous 3d printed model with all on 4 implants was fabricated. Two printed lower complete dentures were used one in group (A) where provisional all on 4 prosthesis was fabricated by conventional pick up technique engaging four titanium sleeves screwed to the four multi-unit abutments. The second printed lower complete denture was used in group (B) to fabricated splinted welded titanium bar provisional all on 4 prosthesis using same pick up technique as in group (A ).load was applied to the two provisional prosthesis and strains were recorded. Data were collected & statistically analysed to compare both groups by independent t-test, the p-value was considered significant at the level of <0.05. Results:The two studied groups showed statistically significant where strain induced around all on 4 implants were reduced in group (B) in compared to group(A) Conclusion: With in the limitation of this study splinting all on four implants in provisional prosthesis reduced stresses and strains around implants in compared to conventional non splinting provisional prosthesis.