Purpose: This study was conducted to measure, in vitro, the chewing load forces transmitted through crowns made of different prosthetic restorative materials onto dental implants. Materials and Methods: A masticatory robot capable of reproducing the mandibular movements and the forces exerted during chewing was used. The forces transmitted to the simulated peri-implant bone during the robot mastication were analyzed using four different occlusal materials: three resin composites and one glass ceramic crown. Results: The ceramic crowns transmitted significantly greater forces (up to +63.06%, P < .0001) than the composite crowns tested. Conclusion: Composite crowns are better able to absorb shock from occlusal forces than crowns made of ceramic material. Int J Prosthodont 2009;22:53–55.