So if ice cream meeting your tooth has you seeing stars, the layer beneath the surface of your tooth (called dentin) has likely become exposed, says Eric Sung, DDS, professor at UCLA’s School of Dentistry. This happens when the hard outer covering of a tooth — enamel above the gum line and cementum on the root — wears away, exposing microscopic tubules in the dentin that lead to the nerve of the tooth. After that, biting into foods that are hot, cold, sweet, or acidic (like tomatoes, oranges, or lemons, whose acids can eat away at enamel and cementum) can cause searing pain.
What’s at the Root of Sensitive Teeth?
Gum recession, when gums pull away from the tooth and expose the root surface, which is common with periodontal disease, plaque accumulates along the gum line. “As plaque builds, the bacteria release toxins that cause the gums to get infected and then recede,” Sung explains.
“Grinding causes teeth to flex and crack, creating a notch that exposes dentin at the gum line, called an abfraction,” Sung says. If you grind, try wearing a nightguard while you sleep to protect your teeth.
Brushing with too much force, with a stiff toothbrush, or even with an old toothbrush can cause abfractions as well. Be sure to brush gently with a soft-bristled toothbrush that you replace every three months whether or not it looks worn.
Also, teeth whiteners give new meaning to the phrase “beauty is pain.” They are notorious for causing tooth sensitivity. “It’s usually transient, but can be long-term where it lasts for days, if not weeks,” Sung says.
How sensitive is too sensitive? Sung offers up a few rules of thumb: “If pain lasts for only a few seconds, it’s not really an issue.” However, if your teeth are sensitive to hot foods and beverages (usually a sign of nerve problems), or if the pain lasts more than a minute or is spontaneous, you’ve earned yourself a trip to the dentist.
Treating Sensitive Teeth
Sung offers these tips for strengthening sensitive teeth:
Go easy — Toothpaste made specifically for sensitive teeth contains either potassium nitrate or strontium chloride, which helps clog the dentinal tubules and prevent the painful stimulus (such as ice cream) from reaching the nerve. But don’t expect immediate results: It will take at least two or three weeks for these pastes to take the edge off.
Filler up — Silver fillings are poor insulators, a particular problem if they’re deep — kind of like wearing metal earrings when it’s freezing outside. “If a filling becomes more sensitive over time, see your dentist,” Sung advises. A new filling or a different type of material may stop the pain.
Cover up — Exposed dentin means a direct path to nerves. Ask your dentist about creating a shield for your teeth with one of a range of coatings — such as fluoride — that effectively reduce sensitivity.