Dental sensitivity occurs when the dentin (middle layer) of a tooth is exposed. Normally, the dentin is covered by enamel above the gum line and by cementum below the gum line. Dentin is made of tiny openings called tubules. Inside each tubule lies a nerve branch that comes from the tooth’s pulp (the nerve center of the tooth). When the dentin is exposed, cold or hot temperature or pressure can affect these nerve branches that can cause sensitivity.
Some causes of dentin exposure include :
- Brushing your teeth too hard. This wears away the enamel layer
- Poor oral hygiene. This may allow tartar to build up at the gum line
- Long-term tooth wear
- Untreated cavities
- An old filling with a crack or leak
- Receding gums that expose the tooth’s roots
- Gum surgery that exposes a tooth’s roots
- Tooth whitening in people who have tooth roots that already are exposed
- Frequently eating acidic foods or drinking acidic beverages