Brushing your teeth seems simple; everyone knows how to do it. But it’s also difficult, because you might be brushing incorrectly every day, and there’s a lot you might not know about it.
Today, let’s do a comprehensive summary of the “small matter” of brushing your teeth, so you can fully understand it all at once!
I. Brushing Your Teeth
The World’s Standard Toothbrushing Posture – The Bass Method
Step 1: Brush the outer surface of your front teeth The bristles should be at a 45-degree angle to the teeth and gums, moving in small circular motions.

Step 2: Brush the inner surface of your front teeth Again, place the brush at a 45-degree angle. For the upper teeth, pull the brush downwards; for the lower teeth, pull it upwards with a gentle stroke.

Step 3: Brush the chewing surfaces of your teeth Hold the toothbrush vertically to the chewing surface and brush gently with short, back-and-forth vibrating strokes.

Step 4: Brush the inner surfaces of your back teeth Hold the toothbrush vertically and use the tip of the bristles to brush up and down along the gaps with small circular motions.

Brush two to three teeth at a time, repeating the circular, massaging motion 8-10 times for a comprehensive cleaning of the teeth and gums from multiple angles.
Step 5: Gently brush the surface of your tongue Brush gently from the inside out to remove food debris and bacteria, keeping your breath fresh.

Some people only brush the outer surfaces, neglecting the inner ones. In reality, you need to brush both the inside and outside of your teeth.
II. Toothbrushes: What kind of toothbrush is best?
1. A short, narrow brush head The American Dental Association recommends a brush head length of about 2.54-3.18 cm and a width of about 0.79-0.95 cm. If the brush head is too big, it can’t move freely in the mouth, missing many difficult-to-reach spots and deep areas. This can cause plaque buildup in these spots, forming tartar, and leading to periodontal disease.
2. Soft bristles or hard bristles? Many experts recommend using a soft-bristled brush. Hard bristles can easily damage the teeth and gums, leading to cuneiform defects and bleeding gums, especially for children whose teeth are just coming in and seniors with severe enamel wear.
3. Rational bristle arrangement When choosing a toothbrush, besides paying attention to the softness of the bristles, their arrangement is also a detail to note. According to the American Dental Association, a good bristle arrangement should have 2-4 rows, with 5-12 tufts per row and a certain distance between them. This is good for both effectively removing plaque and for cleaning the toothbrush itself.
4. The toothbrush handle A good toothbrush also has a well-designed handle. When choosing one, it’s best to select a handle with a non-slip design. There are two main types of non-slip handles on the market: straight and angled. Clinical studies show that straight handles are difficult to control the pressure with, while angled handles make it easier to reach plaque-ridden areas. A 17-20 degree angle between the handle and the head is generally recommended.
You need to replace your toothbrush in the following situations:
- The base of the bristles darkens: Grime slowly builds up at the base of the bristles. Once you notice the color at the base has darkened, it means a lot of dirt has accumulated, and you need to replace your toothbrush.
- The bristles are worn out and misshapen: If the bristles are soft and splayed, and the distance between them has widened, it’s easier for dirt to accumulate at the base. In this case, it’s best to replace the toothbrush immediately.
- After recovering from a cold: A cold usually lasts about 7 days, but the virus can remain contagious for 7-21 days. Even after you’ve recovered, the cold virus can be transferred to your toothbrush. Therefore, you should replace your toothbrush promptly to avoid a secondary infection.
- At least every three months: Three months is the maximum lifespan of a toothbrush because it is often in a damp state, making it a perfect breeding ground for bacteria. Some people experience bleeding gums and swelling after brushing, which is often caused by bacteria from the toothbrush contaminating the mouth, leading to secondary infection!
III. Toothpaste
1. Is fluoride toothpaste good or bad? There’s no doubt that fluoride toothpaste is beneficial. The “Chinese Residents’ Oral Health Guide” states that fluoride toothpaste is effective in preventing dental caries (cavities). Many people worry that long-term use of fluoride toothpaste will cause dental fluorosis. However, dental fluorosis primarily affects teeth development in children who ingest excessive fluoride during their growth period (within 6-8 years old). If you are an adult, it’s not an issue. In short, it’s safe for adults to use fluoride toothpaste. However, since children can easily swallow the toothpaste foam while brushing, it is not recommended for children under 3 years old.
2. You should switch toothpaste brands regularly Using the same toothpaste for a long time can cause some harmful oral bacteria to develop tolerance and resistance, making the toothpaste ineffective. Regularly changing toothpaste brands helps maintain a healthy oral microbiome and contributes to dental health.
3. Should you wet the toothbrush before brushing? If you are using regular toothpaste, wetting the brush or not doesn’t make a big difference. But if you’re using a desensitizing toothpaste, it’s best not to wet it to avoid diluting its active ingredients. Experts have shown that the ingredients in desensitizing toothpaste are different from regular ones. They form a protective layer on the tooth surface. To prevent this active ingredient from being compromised, don’t wet the brush; instead, apply the toothpaste to a dry toothbrush.
4. Family members should not share toothpaste Some families share a single tube of toothpaste, unaware that many oral diseases can be transmitted this way. When sharing toothpaste, if one person has a cold or an oral disease, the cold virus or oral bacteria can easily remain in the bristles. As the toothbrush touches the opening of the toothpaste tube, the viruses and bacteria can be transferred to other people’s toothbrushes. Therefore, it is best for everyone to have their own toothpaste.
Common questions about brushing answered:
1. Do you still need to brush if you have no teeth? Brushing is not just for cleaning the tooth surface but for the entire oral environment, including the gums and tongue. Even if the teeth are gone, the mucosa, gums, and alveolar ridge are still there. Without brushing, pathogenic bacteria in the mouth can enter the body through the esophagus, potentially causing heart and kidney diseases, and even affecting blood sugar stability. Therefore, even if an elderly person has few remaining teeth, they still need to regularly clean their entire oral cavity.
2. Is it bad to brush your teeth immediately after eating acidic foods? If you have just eaten neutral foods like starches, fats, or sugars, you can certainly brush immediately to remove food debris and protect your teeth. However, if you’ve just consumed acidic foods like citrus juices or salad dressings with vinegar, it’s a different story. Acidic foods like strawberries contain oxalic acid and benzoic acid, which can cause demineralization on the tooth surface and reduce its hardness. Brushing immediately afterward can damage the tooth surface and, over time, lead to tooth sensitivity.
3. It’s best not to use cold water for brushing Avoid using cold water. Brushing with warm water close to your body temperature (around 37°C) is most effective.
4. Why should you brush for at least 3 minutes? The average person has 28 teeth, and each one needs to be brushed on three surfaces. If you calculate two seconds per surface, 28 teeth will take at least three minutes to brush.
5. Can mouthwash replace brushing? Some people skip brushing and just use mouthwash to save time. This is incorrect. No oral hygiene measure can replace brushing. While rinsing can remove food debris and some soft plaque, it is not as thorough as brushing. Also, there are non-medicinal and medicinal mouthwashes. Non-medicinal mouthwash mainly functions to eliminate bad breath, similar to chewing gum, with no restrictions on who can use it. Medicinal mouthwash is primarily sold in pharmacies and is used to treat oral inflammation like gingivitis, periodontitis, and mouth ulcers. It should not be used long-term.
6. Is bleeding gums from brushing a sign of a bad toothbrush or “internal heat”? This is a common misconception. Many people believe that bleeding gums are a sign of “internal heat” or a bad toothbrush, and that simply being more careful or using a toothpaste from a TV commercial will fix it. In reality, bleeding gums could be a sign of periodontal disease. This is when plaque, tartar, and other buildup irritate the gums, causing them to become inflamed, swollen, and prone to bleeding. So, if you find that your gums bleed easily when you brush, don’t think it’s “not a big deal.” It’s best to get a checkup at a dental clinic.
7. “Baby teeth will fall out anyway, so why brush them?” This is a huge mistake! Before the age of two, parents should use a clean gauze pad or a finger-worn toothbrush dipped in warm water to gently wipe the baby’s milk teeth to remove plaque. After a baby eats, especially after drinking milk, saliva breaks down the food, leaving a lot of bacteria. If not cleaned promptly, these bacteria will adhere to the baby’s delicate milk teeth and can easily cause cavities. After two years of age, as the baby’s milk teeth fully emerge and their fingers become more dexterous, parents can demonstrate how to brush. You can also stand behind your child and guide their hand to teach them the correct technique, using a toothbrush suitable for their age, at least twice a day.
It’s surprising how much knowledge is hidden within a seemingly simple task like brushing your teeth! You can share this with your family and friends, as they might not know these things either.