Tooth sensitivity to cold and/or sweets may be a sign of a cavity, but it may also be caused by root sensitivity. Teeth are made up of a very hard substance called enamel, which protects the nerve inside the tooth from the stimuli your teeth experience, such as hot, cold, sweets, and chewing.
The surface of the root of the tooth is covered by a material called cementum that is not as strong as enamel, but is protected by the overlying gum tissue. Tooth sensitivity basically occurs when something happens to cause the gum tissue to recede, leaving the sensitive cementum exposed.
One of the most common factors of gum recession is due to the toothbrush. The process is caused by brushing too hard or by using a hard bristled toothbrush, thereby causing the gums to recede. The use of a soft toothbrush with proper technique can help prevent this recession.
Chemical erosion is another cause of root sensitivity. This can occur in people who drink an excessive amount of carbonated beverages or suck on highly acidic foods, such as lemons or limes. The acids in these products can actually eat away the protective enamel coating of the teeth right along the gum line, leading to sensitivity.
This same type of tooth sensitivity may also occur after any dental treatment that affects the position of the gum tissue on the tooth. Some examples would be gum surgeries that expose more tooth structure or the extraction of teeth, which may cause shrinkage of the gum tissue in the area adjacent to other teeth.
The most critical aspect in treating root sensitivity is accurately diagnosing and treating the cause with your dentist. If the cause is not known and corrected, the problem will continue to recur in spite of treatment. Treatment is aimed at coating or sealing the surface of the exposed root to prevent the stimulus (cold, sweets) from transmitting to the nerve of the tooth, causing sensitivity.
There are toothpastes available at most stores that are specifically designed for sensitive teeth. These products decrease the sensitivity over time, although you may find if you stop using them, the sensitivity returns. This may be because the underlying cause has not been treated.
Another option is to have a highly concentrated fluoride gel applied to the sensitive areas at your dentist's office. Your dentist can also seal the area with a thin coating of resin. This is not like a filling, but more like a thin coat of a clear liquid that helps to seal your tooth when it is placed and cured.
Placing restorations (fillings) in the exposed areas will also seal them, but unless the cause of the tooth sensitivity is identified and corrected, the gum may continue to recede past where the filling was placed, causing a new area of root to be exposed below the level of the filling. If the recession is more extreme, a gum graft may be placed, where gum tissue is taken from another part of your mouth and grafted over the exposed area.
By Greggory Kinzer, DDS, MSD