Dental caries, often called “worm teeth”, is one of the common diseases in the oral cavity, which has a great harm and will have a great impact on patients if not treated in time. If not treated in time, it will have a great impact on the patient. Therefore, once found, please follow the doctor’s instructions for treatment immediately, do not delay the condition. Scientific understanding of the danger of dental caries, better return your comfortable life. First, “the definition of dental caries” Many people do not pay enough attention to dental caries, and in the end, it is a small hole without filling a big hole to suffer. If you have dental caries, you should consult the doctor in time for repair, because after treatment of caries, you can stop the development of caries lesions, restore the function and aesthetics of the teeth as soon as possible, maintain the integrity of the teeth, and avoid the premature loss of teeth. Dental caries is due to dental hard tissue decalcification, softening, destruction, and finally formed cavity, if not treated in time, the lesions will become more and more serious, from shallow to deep, from small to large, can be sensitive to cold, hot, sour, sweet and other food stimuli; when the lesion reaches the pulp, caused by pulpitis, at this time, the toothache will be very serious, as the saying goes, “Toothache is not a disease, the pain up to take a life! As the saying goes, “toothache is not a disease, but pain can kill you”; if the lesion is not treated in time, it will cause periapical periodontitis, periapical abscess, and even tooth loosening and loss. The second “the etiology of dental caries” 1, caries bacterial factors in the process of caries occurrence and development, due to the bacteria in the pathogenesis of caries plays a dominant role, therefore, in recent years, the international caries is recognized as a bacterial disease caries. There are many kinds of bacteria, and the most important ones are certain Streptococcus pyogenes and Lactobacillus. These bacteria mix with mucin and food debris in saliva and adhere firmly to tooth surfaces and fossae. This adhesion is called plaque or plaque. A large number of bacteria in plaque produce acid, causing decalcification and dissolution of the enamel surface beneath the plaque. Clinical investigation proved that children with more plaque in the mouth also have more dental caries. 2, dental caries dietary factors In the process of dental caries formation, diet is an important role of bacteria. Food contains a large number of carbohydrates and sugars, these substances not only supply plaque in the bacterial life and activities of energy, but also through the bacterial metabolism so that the glycolysis produces organic acids, acid long-term retention in the tooth surface and grooves, so that enamel demineralization and destruction, followed by some bacteria and make protein dissolution to form cavities. Caries-causing sugars are many, the most important is sucrose. During the period of dental development, nutrition determines the biochemical structure of dental tissues, and well-calcified teeth are highly resistant to caries. If the food in the mineral salts, the main vitamins and trace elements, such as calcium, phosphorus, vitamin B1, D and fluorine and so on insufficient, the caries resistance of the teeth is low, which causes caries onset conditions. 3, dental caries dental factors The morphology, structure and position of teeth have obvious relationship with the onset of dental caries. The fossa of the biting surface of the teeth is a defect left in the developmental process, deep fossa is easy to retain cells and food debris, and it is not easy to remove, easy to induce dental caries. Teeth with insufficient mineralization, especially insufficient calcification, have low enamel and dentin densities, low caries resistance, and are susceptible to caries. The amount of fluorine in the mineralized structure of the tooth is very small, but it is important to enhance the caries resistance of the tooth. Teeth with the right amount of fluorine are less susceptible to caries. The structure and calcification of milk teeth and young permanent teeth are not mature enough, so they are easily affected by caries-causing factors and have a high rate of caries. 4.Salivary factor of dental caries Saliva is the external environment of teeth, playing the role of buffer, washing, antibacterial or bacterial inhibition. The amount of saliva can wash the surface of teeth and reduce the accumulation of bacteria and food debris. Smaller, thicker saliva is easier to retain, encouraging plaque to form and adhere to the tooth surface. The nature and composition of saliva affects its buffering capacity and the living conditions of bacteria. Third, “Classification of dental caries” There are many ways to classify dental caries. Commonly used classification methods are as follows: 1. Classification according to the tissue structure of the teeth; it can be divided into enamel caries, dentin caries, and osteoid caries, etc. 2. 2.Classified according to the site of caries; it can be divided into dentition, facial caries, neighboring surface caries, root surface caries, etc. 3, according to the speed of caries classification; can be divided into chronic caries, acute caries and secondary caries. 4, according to the degree of caries classification; can be divided into shallow caries, medium caries and deep caries. Clinically, it is customary to categorize caries according to the degree of caries to describe caries in order to guide the treatment. (1) shallow caries: refers to the caries is limited to the surface tissue of the teeth, such as tooth enamel or bone. Shallow caries has no self-conscious discomfort symptoms, but changes in tooth color such as chalky white occur and can be detected by examination. There are 3 types of caries color changes in enamel: ① white speckled changes. ② Brown carious spots. Gray-black carious spots. The brown and gray-black changes are due to the decalcification of dental tissues, which are gradually stained by the influence of pigments and proteins in saliva. Shallow caries cavities are characterized by small mouths and large bottoms, such as dentinal caries. Shallow caries in the dentin shows expansion in all directions. The treatment of shallow caries is generally used to remove the net caries, direct filling method to repair the defect. (2) Medium caries: refers to the caries reaches the shallow dentin, also known as dentin shallow caries in medicine. There are self-conscious symptoms of moderate caries: ① discomfort due to embedded food. Sensitivity to cold and hot food stimuli. If the above stimuli are removed, the symptoms disappear immediately. The treatment of moderate caries is generally based on the presence or absence of symptoms of irritation. Whenever there are symptoms of irritation, a cushioning material, such as zinc phosphate adhesive, should be used, and then filled with a permanent material. (3) Deep caries: This refers to caries close to the pulp tissue. The conscious symptoms of deep caries are more obvious than those of moderate caries, and they are very sensitive to cold, hot, sour and sweet foods; the symptoms of embedded foods are aggravated; when the above stimuli are removed, the symptoms disappear immediately. Treatment of deep caries should pay attention to the following issues: pay attention to whether there is spontaneous pain or by the above stimulus, the pain time has not been prolonged. If the pain is prolonged, the pulp is affected by inflammation. The pulp is affected by inflammation as a result of increased inflammation; resulting in pulpal lesions, endodontic treatment (root canal therapy) should be performed. (4) Fierce caries: refers to most of the teeth in a short period of time at the same time in different degrees of acute caries, the lesion area of the hard tissue is highly softened, lighter in color, light brown, soft and moist, easy to dig out. It is common in patients with dry mouth syndrome and head and neck tumors treated with radiation. Most of the teeth, especially the smooth surface of the anterior teeth self-cleaning area is easy to develop. The treatment plan is: ① identify the cause of the disease, for the cause of treatment or remineralization treatment. After removing the decayed material from the affected tooth, the tooth is restored with a material that releases fluoride ions, such as a fluoride ionomer. Root surface caries is not obvious at the initial stage, but it is very harmful at the later stage, and if it is serious, it will directly lead to tooth loss. Root surface caries mainly has the following characteristics: 1, high incidence; the root of the tooth is soft, low mineral content, easier to form caries than the crown. With the increase of age, the incidence of root caries will gradually increase, and the lesions will gradually aggravate. 2, not easy to repair; root caries appeared in the side of the root of the tooth, mostly in the form of shallow disk, the decay area is large and shallow depth, not easy to repair. Moreover, due to the high content of organic matter in the root, it is difficult for the restoration material to be firmly adhered to, and it is easy to suffer from secondary caries after repairing. 3, harmful; adult root caries is often unknowingly occurring and aggravated, when there is a sense of pain often has been injured to the dentin and even deep pulp, and cause pulpitis. Severe root caries can lead to tooth loss. Fifthly, “Treatment of caries” For these patients, it is more important to have fillings as early as possible to stop the rapid progression of caries. Fillings have two benefits: 1. Preventing further progression of the disease and relieving pain. 2. Restore chewing function. With the unceasing progress of science and technology, the current oral treatment equipment and materials also keep up with the trend of the times. It is very convenient and the earlier the filling is done, the simpler it is. It is not only less painful, but also saves money and effort. Sixth “prevention of dental caries” 1, develop good daily oral hygiene habits. Adults should have regular oral checkups and have their teeth cleaned every six months, and often use dental floss, toothpicks and other tools to remove plaque. Eat more fiber-rich foods and massage the gums to accelerate blood circulation and improve local nutrition. In addition, the use of health care toothbrush, use the correct way of brushing teeth can not be ignored. 2. Choose toothpaste with fluoride anti-cavity formula and high quality friction agent. Toothpaste containing fluoride anti-cavity formula (sodium fluoride plus silicon) can cover the teeth with a comprehensive protective layer. For those who have already experienced gum recession, the use of a fluorotellette toothpaste is a reliable way to protect the exposed roots of the teeth. For exposed roots, a gentle, effective rubbing agent removes dirt and plaque without wearing down the root itself.