July 21, 2018
Couple eating ice cream cones, Santa Monica, California

Help for Sensitive Teeth

by Berkeley Wellness  

If you get sharp pangs of tooth pain when drinking cold beverages or eating ice cream, welcome to the hypersensitivity club. At least one-third of adults have sensitive teeth at some point in their lives, with some sources citing much higher rates, particularly among periodontal patients. Most often affected are the canines (the relatively long and pointed teeth, also called cuspids) and the premolars (or bicuspids, between the canines and molars). Other stimuli can also trigger the transient pain—including hot beverages, sweet or sour foods, acidic foods, the touch of the dentist’s sharp tool, or a blast of cold air.

Some people with tooth sensitivity (technically called dentin or dentinal hypersensitivity) regard it as a relatively minor annoyance, but others end up avoiding certain foods or beverages. Worse yet, they may avoid brushing the problematic teeth and skip going to the dentist. But there’s no need to grin and bear it—easy and effective remedies are available.

Why so sensitive?

Tooth sensitivity most often occurs when the dentin—the layer underneath the tooth’s enamel (which covers the crown) and cementum (which covers the tooth’s root below the gum line; see illustration)—becomes exposed, often as a result of gum recession (from periodontal disease or aging, for example), overaggressive brushing, tooth grinding, exposure to acids (from acidic foods or acid reflux), or other factors, including natural wear that occurs over time.

The most widely accepted theory to explain the pain—called the hydrodynamic theory—is that when dentin is exposed, a trigger (such as cold) shifts the flow of fluid in microscopic channels inside the dentin (called dentinal tubules), activating nerve fibers in the tooth’s pulp. Compared to non-sensitive teeth, sensitive teeth have been shown to have a greater number of open tubules in the exposed dentin, as well as tubules that are wider. Most treatments aim to either block the tubules or dampen the nerve response.

Curiously, not all people with exposed dentin have sensitivity—and this may have to do with the subjective nature of pain, or perhaps with individual variations in the composition and flow of saliva, which has a protective effect on enamel. In any case, tooth sensitivity fortunately tends to lessen as people get older, as additional layers of dentin are deposited in the nerve chamber of the tooth and as the dentinal tubules calcify over time.

Some people may also experience acute sensitivity after standard dental procedures, such as fillings, crown restorations, orthodontics, and periodontal surgery, since these procedures can trigger inflammatory processes in the nerve chamber. This usually resolves with time. Bleaching agents used in tooth whitening can also cause short-term sensitivity.

Here’s the drill

If you have ongoing tooth pain, see your dentist to rule out other problems, such as a cavity, cracked or chipped tooth, or fractured dental restoration. If you’re diagnosed with dentinal hypersensitivity, be aware that there may be several underlying causes and that one size doesn’t fit all when it comes to treatment.

You may have to try different approaches and different products for long-lasting relief, but conservative treatments should be attempted first before moving on to more invasive ones. Here are some steps to take:

  • Use a toothbrush with soft bristles and don’t brush with excessive force. Some toothpastes are more abrasive than others, as shown in this chart. Those containing baking soda tend to be less abrasive but they may still contain some abrasive ingredients (such as aluminum hydroxide, hydrated silica, and hydroxyapatite). Whitening toothpastes are most abrasive, but some come with ingredients that help protect enamel.
  • Try desensitizing toothpastes. They typically contain high-concentration stannous fluoride or strontium chloride (to plug the exposed dentinal tubules) or potassium nitrate (to block pain signals from nerves), though it’s unclear how well they work. Use the toothpaste twice a day for at least two to four weeks to see if it helps; you must then continue using it to maintain the benefit. There are also desensitizing oral rinses. Another product, Crest Sensi-Stop Strips, contains an oxalate gel to block the tubules. According to Crest, applying the thin, soft strips to the problematic teeth for 10 minutes provides immediate relief and stops sensitivity for up to a month; some people may need a few applications.
  • Reduce consumption of acidic foods and beverages, which can cause erosion and may trigger pain.
  • If such measures don’t help enough—or if you have severe discomfort limited to just one or two teeth—your dentist can treat you with various topical desensitizing agents (such as fluoride varnishes and gels) or apply sealants to your teeth. Colgate Pro-Argin Sensitive Pro-Relief, available in the U.S. only to dentists, contains calcium carbonate and arginine, an amino acid in saliva. Another dentist product, Colgate Gel-Kam, contains stannous fluoride. Your dentist may also recommend a prescription toothpaste (such as PreviDent or Clinpro) to help desensitize roots. Another option may be laser treatment, though evidence for its effectiveness is equivocal. If the sensitivity is due to gum recession, a periodontist can do a surgical gum graft to cover the exposed root.
  • Keep in mind that a key to preventing and treating tooth sensitivity is to maintain good dental hygiene, which includes brushing at least twice a day with fluoride toothpaste and flossing at least once a day. For how to brush and floss properly, see Basics of Dental Care.

Also see Toothpaste Tips and Myths.