Talk to your dentist about getting a prescription for fluoride toothpaste/treatment. The one I use is a paste you use once a day after brushing, you brush it on

Talk to your dentist about getting a prescription for fluoride toothpaste/treatment. The one I use is a paste you use once a day after brushing, you brush it on and spit it out without rinsing. It has a higher concentration of fluoride than you get in a normal toothpaste. After using it for a while (couple of months) I started noticing a drastic improvement to cold sensitivity. To the point I can bite into ice cream or popsicles without any cold pain.