Introduction: oral cavity is an environment full of bacteria. The temperature, humidity and rich nutrition in the mouth are especially important for the growth of bacteria. Therefore, teeth and gingiva become a hotbed for the growth of bacteria, which may lead to dental diseases. As a result, it is very important to clean your teeth every day. In the following section, we will introduce four kinds of food, which are very beneficial for the health of teeth.

1. Green tea
Green tea is regarded as an anti-aging drink by Japanese people. A lot of researches have shown, green tea has a strong antioxidant capacity, which can prevent a variety of cancer. Often drinking green tea can reduce the risk of cardiovascular disease. Nowadays, experts even point out that, drinking green tea is also very beneficial for the health of teeth. On the one hand, green tea contains a lot of fluorine, which can combine with the apatite contained in teeth, and plays an effect in preventing tooth decay. On the other hand, research show that, the catechin contained in green tea can reduce the streptococcus in mouth, so as to prevent tooth decay and eliminate bad breath.

2. Onion
The sulfur compounds contained in onion are a powerful antibiotic ingredient. The result of experiment shows that these sulfur compounds can kill various kinds of bacteria, including the streptococcus which may cause tooth decay. It is suggested to eat half a raw onion every day, which can not only prevent tooth decay, but can also help lower the level of cholesterol, prevent heart disease and improve human immunity.

3. Mushroom
In recent years, mushroom has become a popular food to improve human immunity. But since 2000, some studies have also found out that mushroom can help protect the teeth. This is because mushroom contains a large number of lentinan, which can inhibit the oral bacteria from forming dental plaque. In addition, mushroom not only has a special taste, but also contains little heat. As a result, it is a good choice for those who want to lose weight.

4. Celery
Celery can help clean your teeth, so as to reduce the chance of tooth decay. This is because the coarse fiber contained in celery is just like a broom, which can sweep away part of the food particles remaining on the teeth. On the other hand, when you are chewing celery, it can stimulate the secretion of saliva, balance the Ph value in the mouth, so as to reach a natural antimicrobial effect.