Dental caries is a chronic disease widely prevalent in human beings with a long history. Dental caries were found on human skulls 250,000 years ago. At present, dental caries has become a worldwide problem. According to the data, there are 1982 and1000 million dental caries in the United States alone. Therefore, the World Health Organization has listed dental caries as one of the three major prevention and treatment diseases. Dental caries is a progressive destruction of enamel, dentin or cementum of teeth under the comprehensive influence of various external factors. Dental caries do great harm to human oral health. If not treated in time, it will also cause pulp diseases, severe pain and restlessness. It destroys the integrity of chewing organs, thus reducing chewing function, hindering digestion and endangering human health. The progress of this disease is very slow. In the process of its slow change, it will not cause any symptoms for a long time, and it is often not easy to be detected and cannot be treated early. In addition, dental caries and its secondary diseases generally do not endanger people's lives and are usually not taken seriously, thus aggravating the severity of dental caries. Especially among teenagers and children, the incidence of dental caries is very high, and getting dental caries will do great harm to children's oral health and even their overall health.

In the past, it was thought that the cause of dental caries was dental plaque attached to the surface of teeth, which was a compound of bacteria and food residue. Bacteria in dental plaque react with food and ferment to produce acid, which corrodes teeth and causes dental caries. With the development of research, this theory has been abandoned. At present, it is believed that dental caries are not caused by dental plaque alone, but by the interaction of host, microorganism, diet, time and other factors, which are called four factors in medicine. Without the participation of any factor, dental caries can't happen. Host refers to the human body itself, microorganism refers to the bacteria in the mouth, diet refers to the food with more sugar, and time refers to the action time of dental caries. To sum up, the cause of dental caries is that there are many kinds of bacteria in everyone's mouth under normal circumstances, among which Lactobacillus and Streptococcus mutans are the most abundant and belong to acid-producing bacteria. Acid-producing bacteria react with carbohydrates in food ingredients to produce acid, which will react with enamel to decalcify and soften the enamel surface, so tooth cavities appear. However, the generation of dental caries takes a time process, and it takes about 1.5 years from the beginning to the time when dental caries can be seen. In addition, different host conditions are also different. Some people pay more attention to oral hygiene, the degree of tooth calcification is good, and dental caries are not easy to occur; However, some people are prone to dental caries and food accumulation due to improper tooth arrangement, and do not pay attention to brushing their teeth. Carbohydrates in food mainly come from sugar, among which sucrose is the most abundant in food and has the strongest effect on dental caries. When it enters the mouth, bacteria directly use these sugars to accelerate reproduction, produce a lot of acid, and corrode the surface of teeth, which is why it was said before that eating more sugar is easy to make teeth worse.

Treating dental caries, especially relieving toothache caused by dental caries, requires a doctor with professional skills. The most commonly used method to treat dental caries is filling teeth, which is often called "filling teeth". This method is suitable for all deciduous teeth and permanent teeth, and a certain hole can be made. The filling method is generally completed by the following steps: rot removal, cavity making, cavity disinfection, bedding, filling and adjustment. Polishing and so on. Some steps take some time, so going to the hospital to see a dentist to treat dental caries is generally not completed at one time, especially those dental caries that have developed into pulpitis often need to go to the hospital for treatment 2-3 times.