What Is Dentine Hypersensitivity? Dentine hypersensitivity is something I see in clinic almost every day — it’s that sharp, sudden pain you feel when your teeth react to cold air, hot drinks, or even brushing. It happens when the dentine (the inner layer of the tooth) becomes exposed — often due to gum recession, enamel wear, or overbrushing. Once exposed, those tiny dentinal tubules act like channels straight to the nerve, causing that familiar zing of discomfort. Traditionally, we used to trea