How enamel protects your teeth

Enamel is similar to the shell of an egg: it protects the softer, more vulnerable part of the tooth inside.

But unlike an eggshell, the thin layer of enamel is tough. In fact, enamel is the hardest substance in the body. It can withstand decades of biting, chewing and crunching – with some luck and good dental care.

What makes teeth white?

Tooth enamel might seem white, but it’s actually the layer underneath – dentin – that makes the tooth appear lighter or darker. Enamel is semi-translucent. At least it starts that way.

Over time, coffee, tea, wine, cigarettes and other substances can stain your enamel, making it off-colour, yellow or grey.

From enamel erosion to cavities

As tough as tooth enamel is, it’s not indestructible. Acids from foods and bacteria can eat away at it, causing erosion and cavities.

In this picture, cavities are forming in the centre.

Enamel can also be chipped or cracked. And unlike bone, enamel can’t grow back on its own. The damage is permanent.

Tooth decay and sensitivity

What happens when tooth enamel is damaged? The exposed part underneath becomes vulnerable to decay. Cavities aren't the only problem.

Teeth with damaged enamel can become sensitive to extreme temperatures. Suddenly, eating ice cream or sipping hot tea can be painful or unpleasant.

How bacteria destroys enamel

After you eat, certain bacteria in your mouth feast on sugars from sweet foods and starches. This makes acids that can destroy enamel. The green rods in this slide are bacteria that cause gingivitis.

The acids found in fizzy drinks, juices and some other drinks are harmful, too. Some are more corrosive than battery acid.

Over time, these acids cause erosion, literally shrinking the size of the tooth.

Wine tasters, beware

Wine tasters may be at high risk for enamel stain and erosion.

Why? Sipping wine many times a day – and swirling it around in the mouth – increases the enamel’s exposure to damaging acids.

Eating and digestive problems

When stomach acid gets into the mouth, it can have a corrosive effect on the tooth enamel.

Any condition that causes frequent vomiting, for example gastrointestinal problems such as acid reflux, and eating disorders such as bulimia (shown here), can damage tooth enamel.

The problem with dry mouth

Saliva naturally neutralises acids in the mouth that erode teeth. It also resupplies minerals to strengthen tooth enamel.

If you have a dry mouth – caused by a medicine side effect or a health condition – the acids stay around longer, causing greater damage.

Grinding teeth

Another cause of tooth enamel damage is bruxism – or teeth-grinding. Over time, the constant clenching and friction can wear down or fracture the enamel. In this picture, teeth grinding has ground down the upper and lower front teeth.

Studies show almost 70% of bruxism is caused by stress or anxiety that affects people subconsciously while they sleep. Reducing stress may help. Some people wear a special mouth guard to bed.

Your mouth is not a bottle opener!

Your mother was right: never open bottles, packages or other containers with your teeth. You might permanently chip or crack the enamel.

Gnawing on anything else – like pens or fingernails – or chomping on seeds, popcorn kernels or ice could have the same result.

Kids and tooth enamel erosion

Many experts believe that tooth enamel erosion is on the increase – especially in children. Why? Some say that kids are drinking too many acidic and fizzy drinks. Plus, some estimates suggest 15% to 33% of children grind their teeth regularly, for example during exam stress.

Drinking less tap water with protective fluoride – and more bottled water without it -- could also be part of the problem.

Tips to fight tooth enamel erosion

There are simple ways to reduce tooth erosion. Brush at least twice a day and ideally after eating or drinking. Use a soft toothbrush and fluoride toothpaste. Don’t rinse as this washes away protective toothpaste.

Avoid food high in fermented carbohdrates, like biscuits or fizzy drinks. You can  have some milk or a piece of cheese after a meal to help neutralise acids.

Another way to counteract the effects of acids is to chew sugar-free gum after eating. This will  stimulate your saliva production.

Improve your dental hygiene

Floss your teeth; don’t use toothpicks.

Brush your teeth gently. Scouring teeth with a hard-bristled toothbrush can damage enamel.

Be careful when using teeth-whitening products, which can damage enamel if used improperly or too often.

If you need help on how to care properly care for your teeth, just ask your dentist.

Related reading

• 10 tooth brushing mistakes
• 5 bad habits and how to break them
• Best foods for children’s teeth
• How stress affects your oral health
• Who uses mouth guards and why?
• What causes bad breath