Aim of the study: The aim of present study was to evaluated the effect of storage in artificial saliva and cyclic loading on fracture resistance of new CAD/CAM provisional prosthetic material in comparison with two currently used provisional prosthetic materials namely Protemp4 and VITA CAD- tempMaterials and Methods: Thirty freshly extracted intact human lower first molars with completely formed roots were collected. each tooth was vertically embedded in an acrylic block. Teeth were machine milled using a lath to achieve a standardized coronal preparation with 1 mm shoulder finishing line and 10° axial taper with the side wall length 4.5 mm with flat occlusal reduction, A groove was then cut in the occlusal surface along central fissure mesiodistally. The thirty teeth were divided into two groups of fifteen teeth each according to the tested provisional crown system. Group I: Machinable provisional system. (VITA CAD-Temp). Group II: Two pastes bis-acrylic composite system for provisional prosthetic restoration (Protemp 4). Each group was divided into three subgroups: Subgroup I: Samples tested after cementation (control group). Subgroup II: Samples subjected to cyclic loading before fracture resistance testing. Subgroup III: Samples subjected to storage in artificial saliva before fracture resistance testing. All samples were individually & vertically mounted on the Universal Testing Machine. The samples were subjected to a slowly increasing vertical load (1mm/min) until the fracture occurred.Results: There was no statistically significant difference between control and cyclic loading; Stored material showed the statistically significantly lowest mean fracture resistance. As regards Control as well as Cyclic loading: Protemp4 showed statistically significantly higher mean fracture resistance than VITA CAD-temp. As regards stored material: Protemp 4 showed statistically significantly higher mean fracture resistance than VITA CAD-temp.Conclusion: Cyclic loading without storage in artificial saliva did not significantly affected the fracture resistance of both provisional prosthetic systems. Storage in artificial saliva significantly affected the fracture resistance of both provisional prosthetic systems. Protemp 4 showed higher fracture resistance than VITA CAD-temp provisional prosthetic systems.