Desensitizing agents are substances that reduce the sensitivity of your nerves or block the transmission of pain signals from your teeth to your brain. They can be applied directly to your teeth by your dentist or by yourself at home using toothpaste, gels, rinses, or strips. Some examples of desensitizing agents that you can get in the dental office are potassium nitrate, fluoride, strontium chloride, oxalates, glutaraldehyde, or calcium phosphate.