Читать книгу Applied Oral Physiology - Robin Wilding - Страница 20

When dentin is exposed to oral fluids because of enamel wear, or enamel caries, bacterial products may diffuse down the dentinal tubules and cause a hypersensitive response from the odontoblast to normal stimuli. Cutting or grinding procedures on exposed dentin to remove dental caries is painful and usually requires anesthesia. It has been suggested that a normally cooled preparation of a completely caries-free tooth would not be particularly painful as the dental pulp is not hypersensitive. For obvious reasons this is not routine. The most common clinical sign of dentin hypersensitivity is a painful response of the pulp–dentin to hot and cold foods.

When odontoblasts are subjected to chemical or physical irritants, they increase in size and start laying down new peritubular dentin. They also lay down dentin in the roof of the pulp chamber, called secondary dentin, and retreat from the irritation behind this layer.