Twenty all-porcelain In-Ceram bridges were resin bonded to natural teeth on a study model. Ten of the test specimens were fixed on abutments placed directly in resin, and 10 were supported by an artificial periodontal membrane. Incisal forces of physiological magnitude and direction were applied in three bridges of both groups (test samples) in an artificial oral environment (1250,000 cycles). The fracture strength of the six test and 14 control specimens was tested in a universal testing instrument and the rupture strength measured. There was no significant difference between the fracture strength of the test and control samples. The artificial periodontal membrane around the abutment teeth did not reduce the fracture strength of the In-Ceram bridges.