Lemon and teeth: effective whitening trick or dangerous for enamel?

It's true that lemon can give the impression that your teeth are whiter, but be careful: used too often, it can also weaken the enamel. Its high acidity can remove some surface stains, but without really whitening in depth. Result: a slightly brighter smile in the moment, but also a risk of sensitivity and dental erosion over time.

So, is it really a good idea to use it? Here's what you need to know before trying this very popular trick.

This fruit is rich in citric acid, a compound found naturally in citrus fruits. Its pH generally ranges between 2 and 3, which makes it particularly harsh on our teeth.

To understand its effect, you need to know that tooth enamel starts to demineralise when the pH drops below about 5.5. Except that its juice is far more acidic than that. When applied directly to the teeth, it can gradually dissolve some of the enamel's minerals.

Some people notice that their teeth seem lighter after several uses. But scientific studies don't show that lemon has any real whitening power comparable to that of clinically proven whitening products.

Effective whitening treatments work by changing the pigments responsible for staining. Lemon, on the other hand, mainly works by attacking the surface of the tooth.

That's exactly where the problem lies. Because lemon can give the impression that teeth are whiter, for several reasons:

• It removes some surface staining,

• It makes teeth momentarily brighter,

• It removes part of the enamel's thin protective layer.

But this visual effect has nothing to do with real whitening. Worse still: as the enamel gets thinner from being attacked by the acid, the tooth becomes more translucent. Over time, the dentin underneath, which is naturally more yellow, ends up becoming more visible.

In the end, you often get the opposite of what you were after: teeth that look darker and more fragile.

That's why most dentists advise against using it regularly. If you want a brighter smile without harming your oral health, other options exist, and they're much safer.

The real problem is its acidity. With its pH, lemon juice is much more acidic than the threshold at which enamel starts to break down.

In short, every time you expose your teeth to this acid, you weaken the protective layer that covers them a little more. And unlike other parts of the body, enamel doesn't regenerate once it's damaged. So the damage is permanent.

At first, you may not really notice the erosion, but over time certain signs can appear:

• The edges of the teeth become more transparent,

• The surface looks smoother or shinier,

• Tiny cracks form,

• They take on a more yellow tone because the dentin underneath becomes more visible.

When the enamel gets thinner, the inside of the tooth is less protected against outside attacks. You may then feel pain or discomfort when eating or drinking cold, hot, sweet or acidic foods.

This sensitivity is often the first sign of exposure to acids that's too frequent. Some people also feel pain when brushing or when breathing in cold air.

Your gums aren't spared either. Direct contact with lemon juice can irritate them, especially if you use it often or if your gums are already fragile. Redness, burning or temporary discomfort can then appear.

If you already have sensitive teeth, using this fruit is really not advisable. It's best to opt for gentler solutions to preserve the balance of your mouth and your oral health in the long run.

As we've said, dentists don't recommend this option. But if you really insist on using it for whitening, avoid doing it every day or repeating the application too often.

The more your teeth come into contact with acidity, the greater the risk of damaging the enamel. Occasionally is less serious than every day. But keep in mind that even occasional use isn't risk-free. Using this juice in your toothpaste shouldn't become a habit.

If you've already used it, here are a few tips to limit the damage:

• Rinse your mouth well with plain water,

• Wait at least 30 minutes before brushing,

• In the hours that follow, avoid acidic foods or drinks,

• If your teeth become sensitive, usea specific toothpaste.

This 30-minute pause is important. Right after contact with the acid, your enamel is more fragile. If you brush straight away, you risk wearing it down even more.

To get a brighter smile without attacking the enamel, it's best to avoid homemade recipes that are too acidic or abrasive. There are solutions that are far more respectful of oral health, while still limiting the appearance of stains.

Among the things that work:

• Brush your teeth regularly and thoroughly,

• Use an electric toothbrush to better remove plaque,

• Cut back on coffee, tea, red wine and tobacco, which encourage staining,

• Get a scaling done by your dentist at regular intervals,

• Choose products specifically designed to protect the enamel.

Some natural methods can also complement good oral hygiene, provided they're neither too abrasive nor too acidic.

You need to keep in mind that no natural method can whiten teeth radically in just a few days. Promises of spectacular results are often exaggerated and can even damage the enamel.

It doesn't regenerate on its own. However, you can limit the damage from getting worse and strengthen the remaining teeth with appropriate care.

If you think you've weakened it after using lemon, baking soda or other home remedies several times, here are a few good habits to adopt:

• Stop aggressive whitening treatments right away,

• Switch to a toothpaste for sensitive teeth,

• Cut back on acidic foods and drinks,

• Keep up flawless oral hygiene,

• Consult a healthcare professional quickly.

Certain signs should alert you: strong sensitivity to hot or cold, teeth that look more yellow than before, transparent tooth edges or discomfort when brushing.

In these cases, the wisest thing to do is to book an appointment with a dentist. An examination will help assess the state of the enamel and put solutions in place to protect your teeth in the long run.