Small Fiber Neuropathy affects two types of nerve fibers: unmyelinated and myelinated. The usual places where small fiber neuropathy occurs does not include the teeth. It does include places on the face and can cause dry eyes, dry mouth, sensitivity to hot and cold, but not specifically affecting the teeth. Now, Neurontin is used to treat small fiber neuropathy and should help the symptoms, however, it may not help with your teeth.