There are an assortment of microscopic tubules that connect the pulp (nerve inside the tooth) to the outside of the roots. Gum recession, whether natural or pathological, exposes some root structure and these tubules with it. Sudden pressure and temperature changes outside the tooth can be conducted through the fluid in these tubules to the pulp, which you then perceive as pain.
Sugary foods create an osmotic pressure differential between the inside and outside of the tooth as the sugar dissolves in your saliva. Water rushes out of the dentinal tubules to dilute the sugar outside the tooth, and the resulting change in pressure causes a brief twinge of pain.
Latest Answers