Feeling a jolt of pain in your teeth when cold air hits them is a common experience. This sharp, sudden pain indicates tooth sensitivity, also known as dentin hypersensitivity. It can make everyday activities like breathing in cold air, enjoying certain foods, or even brushing your teeth uncomfortable. Understanding why this happens can help you find relief and maintain your oral health.
The Mechanism of Tooth Sensitivity
A tooth has several layers. The outermost layer of the tooth crown is enamel, a hard, protective substance. Beneath the enamel lies dentin, a softer layer that contains millions of microscopic channels called dentinal tubules. These tubules extend from the outer surface of the dentin inward to the pulp, the innermost part of the tooth containing nerves and blood vessels.
When dentin becomes exposed, stimuli like cold air can cause the fluid within these dentinal tubules to move rapidly. This fluid movement stimulates the nerves located within the pulp, leading to the sharp, fleeting pain associated with tooth sensitivity. This process is explained by the hydrodynamic theory of pain.
Common Causes of Tooth Sensitivity
Tooth sensitivity arises when the protective enamel or gum tissue wears away, exposing the underlying dentin. One common cause is gum recession, where the gum tissue pulls back from the teeth, revealing the root surfaces normally covered by a thin layer called cementum. Since cementum is softer than enamel, it wears away more easily, exposing the dentin beneath.
Enamel erosion is another common cause, often from consuming acidic foods and drinks, or aggressive brushing techniques. Tooth decay and cavities also expose dentin as bacteria break down the tooth structure. Fractured or cracked teeth, as well as worn or damaged fillings, can create pathways for stimuli to reach the dentin and nerves. Teeth grinding, known as bruxism, can wear down enamel over time, increasing sensitivity.
Managing and Preventing Tooth Sensitivity
Managing tooth sensitivity involves at-home care and professional dental interventions. Using desensitizing toothpaste, containing compounds like potassium nitrate or stannous fluoride, can help block pain signals to the nerves or occlude the dentinal tubules. Switching to a soft-bristled toothbrush and using a gentle brushing technique can prevent further enamel wear and gum recession. Limiting acidic foods and beverages and using a nightguard if you grind your teeth are beneficial.
For more persistent or severe sensitivity, a dentist can offer various treatments. Professional fluoride treatments strengthen enamel and reduce sensitivity by forming calcium fluoride crystals that obstruct the dentinal tubules. Dental bonding or sealants can cover exposed dentin, while gum grafts may be performed for severe gum recession to cover exposed roots. For persistent pain, a root canal may be considered to address the nerve directly. If sensitivity continues despite home remedies, or if the pain is severe, consulting a dental professional is advised to rule out serious underlying issues.