Tooth Enamel: What Helps, What Hurts

Tooth Enamel: What Helps, What Hurts

 

The outer surface of teeth, called enamel, is designed to last a lifetime. "Enamel is the hardest substance in the body," says dentist Leslie Seldin, DDS, a spokesperson for the American Dental Association. Some wear and tear of tooth enamel is inevitable. But Seldin says there's plenty you can do to keep your enamel strong. Start with these eight steps.

1. Limit Sugary Soft Drinks and Foods

Sugar leads to the production of acids in the mouth, which soften and eventually wear away at enamel. Chewy candies that stick on your teeth are particularly damaging. So are soft drinks. Along with sugar, soft drinks may contain citric acid and phosphoric acid, making them even more acidic. Artificially sweetened soft drinks are a smarter choice than sugary soft drinks. But sugarless sweeteners are acidic and may erode enamel over time. The best choice when you're thirsty: a glass of water.

2. Help Yourself to Foods That Protect Enamel

Calcium in foods neutralizes acids in your mouth. Calcium is also an essential mineral needed to keep bones strong. Milk, cheese, and other dairy products all help protect and strengthen enamel, says Pamela L. Quinones, RDH, president of the American Dental Hygienists’ Association. Choose low-fat or fat-free dairy to help keep fat and calories to a minimum. If you frequently drink orange juice, O.J. with added calcium may be the best choice. Calcium buffers the normal acidity of orange and other citrus juices.

3. Avoid Over-brushing

Brushing too vigorously can wear down enamel. "Always use a soft brush and brush gently," says Seldin. Hold the brush at about a 45-degree angle to your gums and move it back and forth in short strokes, about the distance of one tooth. Don't brush immediately after eating sweets or citrus fruits. Acidic foods temporarily soften enamel and may make it more susceptible to damage from brushing. Wait for up to an hour after you eat, giving your enamel time to re-harden. Then brush your teeth.

4. Treat Heartburn and Eating Disorders

With severe heartburn, stomach acids may escape up into the esophagus. If those acids reach your mouth, they can erode enamel. The eating disorder bulimia, in which people vomit food after they eat, is another threat to enamel. If you have symptoms of heartburn or bulimia, talk to your doctor about treatment.

5. Beware of Chlorinated Pools

When swimming pools aren't chlorinated properly, the water may become too acidic. Tooth enamel exposed to pool water can begin to erode. In a study by the Centers for Disease Control, 15% of frequent swimmers showed signs of enamel erosion, compared to only 3% of people who don't swim. Check with the recreation center or gym where you swim to make sure the pool's pH is checked regularly. While swimming, keep your mouth closed to avoid exposing your teeth to chlorinated water.

6. Be Alert to Dry Mouth

Saliva helps wash away food and bacteria that can lead to cavities. Saliva also neutralizes acidic foods. People with xerostomia, or very low salivary levels, often show signs of enamel erosion. Drink water often to keep your mouth clean and moist. If you exercise strenuously, be sure to rehydrate during and after your workout. Chewing sugarless gum or sucking on sugarless hard candy can stimulate saliva production. Some medical conditions and certain medications can cause dry mouth. If dry mouth persists, talk to your doctor.

7. Avoid Grinding Your Teeth

Some people grind their upper and lower teeth together, especially at night. "Over time, grinding can wear down the enamel surface and destroy teeth," says dentist Richard Price, DMD, a spokesperson for the American Dental Association. "If you notice yourself clenching your jaw or grinding your teeth, talk to your dentist." Custom-fitted tooth guards can help protect teeth from damage. 

8. Get Regular Check-ups

To keep your enamel strong, see your dentist every six months for a check-up and teeth cleaning. Your dentist can spot signs of trouble, such as cavities or tooth grinding, before they do extensive damage to your enamel. Your dentist will also make sure that you're getting the right amount of fluoride to protect your teeth. Fluoride hardens and protects tooth enamel. If your water supply is not fluoridated, ask your dentist if you need to take extra steps to protect your teeth. Your dentist may recommend fluoride supplements, mouthwashes, or coatings for your teeth.

 

Neuroscientists prove what we always suspected: the two sexes see the world differently

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If you’ve ever found yourself at a paint store with a member of the opposite sex trying to decide between, say, “laguna blue” and “blue macaw,” chances are you’ve disagreed over which hue is lighter or looks more turquoise.

Take comfort in the fact that the real blame lies with physiology: Neuroscientists have discovered that women are better at distinguishing among subtle distinctions in color, while men appear more sensitive to objects moving across their field of vision.

Scientists have long maintained that the sexes see colors differently. But much of the evidence has been indirect, such as the linguistic research showing that women possess a larger vocabulary than men for describing colors. Experimental evidence for the vision thing has been rare.

That’s why Israel Abramov, a psychologist and behavioral neuroscientist at CUNY’s Brooklyn College, gave a group of men and women a battery of visual tests. Abramov has spent 50 years studying human vision—how our eyes and brain translate light into a representation of the world. He’s curious about the neural mechanisms that determine how we perceive colors.

In one study, Abramov and his research team showed subjects light and dark bars of different widths and degrees of contrast flickering on a computer screen. The effect was akin to how we might view a car moving in the distance. Men were better than women at seeing the bars, and their advantage increased as the bars became narrower and less distinct.

But when the researchers tested color vision in one of two ways—by projecting colors onto frosted glass or beaming them into their subjects’ eyes— women proved slightly better at discriminating among subtle gradations in the middle of the color spectrum, where yellow and green reside. They detected tiny differences between yellows that looked the same to men. The researchers also found that men require a slightly longer wavelength to see the same hue as women; an object that women experience as orange will look slightly more yellowish to men, while green will look more blue-green to men. This last part doesn’t confer an advantage on either sex, but it does demonstrate, Abramov says, that “the nervous system that deals with color cannot be wired in the exact same way in males as in females.” He believes the answer lies in testosterone and other androgens. Evidence from animal studies suggests that male sex hormones can alter development in the visual cortex.

While Abramov has an explanation for how the sexes see differently, he’s less certain about why. One possibility—which he cautions is highly speculative—is that it’s an evolutionary adaptation that benefited hunter-gatherer societies: Males needed to see distant, moving objects, like bison, while females had to be better judges of color when scouring for edible plants.

Someday, further studies could reveal whether these traits could have implications for how men and women perform in fields such as the arts or athletics. At the very least, Abramov says, women probably have an edge nabbing the ripest banana on the shelf.