Generally labeled fluoride-free toothpaste usually includes the following contents: 1. Black sister toothpaste, toothpaste containing xylitol, and fluoride-free. The second is double-sided toothpaste. The third is Yunnan Baiyao toothpaste. The fourth is Tianqi toothpaste. These toothpastes usually contain no fluoride, so they are suitable for people in high fluoride areas, especially children under six years old, to avoid dental fluorosis. However, if fluoride toothpaste is used in low fluoride areas, it can prevent dental caries, and it is not easy to get dental caries, so it should be selected according to different situations. If fluoride toothpaste is used in low fluoride areas, it is best to do it under the supervision of parents. Children should avoid fluoride teeth when swallowing this fluoride toothpaste. The effect of fluoride on caries prevention is manifested in three aspects: 1. After the teeth grow out, the surface tooth mechanism is not very solid, and fluoride from outside can also penetrate into the tooth mechanism, making it sound. 2. Fluorine can reduce the adhesion of dental plaque bacteria on the tooth surface and also reduce the acid production of bacteria. 3. There is proper fluoride in the mouth. When dental caries occur, fluoride can inhibit the whole process of tooth demineralization. After the acid in the mouth is removed, fluoride will continue to promote the recovery of demineralized teeth.