The fiber-reinforced upper complete denture base was studied to improve the mechanical properties and the performance of the molding of acrylic resin denture base. The carbon and the organic fibers were used to reinforce the upper acrylic resin complete denture bases which are brought about the most high frequency of fracture. The positions of reinforcement were respectively near the front teeth and the palatal area of upper complete denture base. The purpose of such the studies is to strengthen the upper denture base of which the thickness of palatal area is thin. As the applied load on the denture base was assumed as the flexural de formation of the denture base, the four-point loading system was adoptted for these tests. Then, the strain destribution and the stiffness of denture base were examined, and the effec tiveness of reinforcement for the fiber-reinforced denture bases were investigated. And so the flexural deformation and fracture of the upper complete denture base caused with the occlusal force were basically considered, and the progress of fracture and the fracture modes of the denture base were examined.
