Patients will have touch (sensory) testing by the following three methods: 1) a warm sensor applied to the gums and the patient will rate when they first feel heat and when the heat feels painful; 2) the bristles of a small paint brush will be gently stroked across the gums, and the patient will say whether it feels painful; 3) a light touch will be applied to the gums with a small needle, and the patient will rate the pain intensity following the touch.