Some myths spread faster than spilt water on a tabletop. While it is true that word of mouth is often responsible for this phenomenon, today it is the Internet that spreads the majority of the hoaxes we later hear and sometimes come to believe.

According to an article published by Redacción Médica, more than half of the patients who visit their doctor have previously searched the Internet for information on the state of their health.

It’s normal to have doubts and to want to check if, for example, you have bleeding gums, sensitive teeth, or a stain on your teeth. The problem isn’t asking, but finding answers in the wrong place.

You have to learn to filter online information. That’s why today we want to talk about some of the most common dental myths.

“You can use lemon to whiten your teeth”

Let’s be clear about this from the beginning. Not only is this claim completely false, but it is also very dangerous.

On YouTube, Instagram and TikTok you can find all sorts of videos showing YouTubers brushing their teeth with a mixture of baking soda and lemon, showing the “miraculous” result of whiter teeth. Do you know why? Because lemons are so acidic that they basically weaken and dissolve the enamel. That’s why your teeth immediately look whiter.

However, the damage acid causes to the enamel is irregular, while baking soda also produces deep ridges. This means that if you eat food with a dark colour, your teeth will become stained again, but more deeply so, accentuated in the ridges created by the baking soda and in the irregular areas caused by the acid.

In the long term, trying to whiten your teeth at home using lemon or activated carbon (another product widely shown on social media) has the unique result of causing wear to your teeth and making them feel sensitive.

The micro-influencers who create this kind of content send a very dangerous message to all of their subscribers. So take heed: if you want to whiten your teeth safely and professionally… visit your dentist!


“It’s normal for your gums to bleed from time to time”


You may have become used to seeing a little trace of blood when you brush your teeth. However, while it’s not something you should panic about, it’s not normal. Healthy gums don’t bleed. If your gums do bleed when you brush your teeth, it means your mouth is telling you something is wrong.

Bleeding gums when brushing your teeth is the most common symptom of gum disease, which is normally caused by the accumulation of tartar and bacterial plaque. While this pathology represents low risk to your health in its early stages, these are symptoms that mustn’t be ignored. If the plaque continues to spread and damage the tissue, the consequences will be much greater.

If your gums bleed from time to time, visit your dentist so that they can study your condition and solve the issue.

More information on gum disease


“Babies can’t get tooth decay”

You only have to realise that “baby bottle tooth decay”, a rampant form of tooth decay, exists to know that this claim too is a myth. Tooth decay can appear in milk teeth if babies keep the bottle in their mouth for too long, or if you dip their dummy into different substances like sugar or honey to keep them happy.

Did you know that the first visit to a dentist is recommended before the child is a year old?

And that’s not a myth! The paediatric dentistry speciality studies the oral health of children and babies, detecting habits which could lead to dental misalignment and making sure that their teeth grow in properly.


“You must brush your teeth three times a day”


Believe it or not, this is a myth! In fact, it is one of the most widely known myths on oral and dental health, probably because it’s half true. We generally say that you should brush your teeth 3 times a day, but in fact it is important to brush them every time you eat to prevent the accumulation of plaque. It is also advisable to brush them as soon after eating as possible, and not leave it until a while afterwards.

A few minutes after eating, the natural pH in your mouth turns into acid due to the action of bacteria on the food you have eaten. These acids attack and weaken the enamel. This means that the longer you wait to brush your teeth, the more effect the acids will have, and the sooner you will suffer from tooth decay.

A tip? Always carry a travel toothbrush with you or keep one at work. This means that you won’t have to neglect your dental hygiene, even if you’re in a hurry!


“Brushing your teeth 3 times a day is enough”

This is false. Not because 3 times a day aren’t enough, but because brushing is not the only way to take care of your dental health. For correct oral and dental hygiene, you should also use tools like dental floss and mouthwash. These will help to remove any leftover food between your teeth and your gums and to keep the tissue in good health.

On the other hand, you should also visit your dentist at least once a year. No matter how good your dental hygiene, other factors may have an influence on your oral health, like genetics or what you eat. With periodical check-ups, the dentist can keep your mouth and teeth in good health so that you have nothing to worry about.


These are only some of the many online myths existing on the subject of dental and oral health. We recommend that you take everything you read about health with a pinch of salt and treat it with common sense. Choose reliable sources and compare the information on several websites. And if you have any specific doubts about your oral health, visit your dentist. That’s why there are professionals specialised in taking care of your mouth!

Write to or call us if you’re looking for a dentist in Donostia (San Sebastián).