The material specified for the bite plate in your model is crystalline silicon, which is almost as hard as steel. I would have thought a bite plate would have been made of a hard plastic like Acrylic, or maybe a soft material like ethylene vinyl acetate (EVA), which is used for Night Bite Guards to protect teeth from grinding.
For reference, here are the Young's Modulus values of the stiffness of each material including the two in your model.
Steel = 200 GPa
Silicon = 166 GPa this is what you are using for the bite plate
Tooth = 20 GPa this is what you are using for the teeth
Acrylic = 2.7 GPa
EVA < 0.1 GPa
Please reply with what you intended to use for the bite plate.