Simple, inexpensive, and effective cures for painful and/or serious problems. That’s the goal—the dream for pretty much everything in the field of medicine. Dentistry, a specialized field of medicine that it is, shared this common goal. Now, although sensitive teeth may not be the most serious problem that can arise in your mouth, it definitely has the potential to be one of the most distracting in your daily life. The pain from sensitive teeth can bother you every day, day in day out, driving you to look for a seriously effective cure right away. Of course, such a solution should be inexpensive and easy to use to make it practical to alleviate the sensitive tooth pain without the cure causing more discomfort. That’s clearly part of the appeal of sensitive toothpastes. They are relatively inexpensive replacements for something that’s already part of your daily oral care routine. All this leads to the inevitable question—How do those sensitive toothpastes really work?
Sensitive teeth, at the most basic level, happen when the middle layer of the tooth, the dentin, is open and exposed instead of being covered by a protective layer of enamel. Because the dentin layer is made up of tubules, tiny tube-like structures that connect to the inner layer of the tooth (which contains the nerves in each tooth), it can allow irritants to reach the nerves and cause sensations ranging from mild irritation to sudden, sharp pains. There are numerous irritants that can cause pain, and avoiding them may not be practical, or even possible. Enter sensitive toothpaste—which generally works in one of two ways.
The first way that a sensitive toothpaste can help treat sensitive tooth pain is by including an active ingredient that acts on the nerves, numbing them slightly and making them less sensitive to painful stimuli. Potassium nitrate is the ingredient approved by the US Food and Drug Administration to be used in anti-sensitivity products to help desensitize nerves in the teeth. Studies have found that it is helpful and effective for treating sensitive tooth pain. Toothpastes that contain potassium nitrate, unsurprisingly, are not a magic solution that stops sensitive tooth pain the second they are applied. Rather, they gradually work over the course of a week or two to lessen sensitivity and thereby lessen sensitive tooth pain. Unfortunately, some patients who use these types of toothpaste find that the protection against sensitivity fades after they stop using the toothpaste. It’s possible that long term use of a potassium nitrate toothpaste may be necessary to keep protection against sensitivity.
The second way that a sensitive toothpaste can prevent tooth pain is by occluding, that is blocking, the tubules and providing protection for the nerves and inner layers in that fashion. There are several ingredients that have been tested to determine how well they can work to prevent sensitivity in that fashion. Not surprisingly, since fluoride is one of the ingredients known to strengthen tooth enamel, it is often included in sensitivity toothpaste formulas. Calcium crystals in several forms have also been tested in the fight against sensitivity. A 2014 study found that calcium sodium phosphosilicate works at least as well as potassium nitrate against sensitivity, and its effects may be more long-lasting. A 2018 study found that a calcium & fluoride crystal, fluoro calcium phosphosilicate, may work even better than calcium sodium phosphosilicate. Nanohydroxyapatite, a form of calcium crystal that matches the calcium crystals in tooth enamel, has been shown to be effective for blocking dentin tubules and for remineralizing tooth enamel surfaces in general. In fact, a 2014 review of existing research on nanohydroxyapatite found it effective against sensitivity, particularly for the sensitivity that often accompanies tooth whitening.
So, if you are suffering from sensitive teeth, it’s a good idea to touch base with your dental care team to make sure that the sensitivity is not a symptom of a more dangerous underlying condition. Once you and your dental care team have established your causes for sensitive teeth are appropriate to treat at home with a sensitivity-fighting toothpaste, you can consider if you would be more comfortable with nerve desensitizing agent or an enamel repairing agent, like a toothpaste that includes nano hydroxyapatite.