Commonly known as “tooth decay”, it is a disease of chronic progressive destruction of dental hard tissues under the joint action of four factors: bacteria, food, host and time, and is one of the common diseases of human beings. ˜ The residual crown and root caused by severe caries stimulate the surrounding soft tissues and so on, causing ulceration and erosion. ˜ It becomes a focal point, the home base of bacteria. The toxin of bacteria can go to all parts of the body through blood flow. Caries lesion can cause iridocyclitis, rheumatoid arthritis, nephritis, rheumatic heart disease or viral myocarditis. The progression of caries can then cause pulpitis. It is generally divided into acute pulpitis and chronic pulpitis. Acute pulpitis, as the saying goes, “toothache is not a disease, but pain really kills”, refers to this disease, when the pain is severe and unbearable, and it is often more severe at night than during the day, and the pain is aggravated by cold or hot stimulation. The development of pulpitis comes to periapical inflammation, the patient dare not bite, sometimes the tooth has elongation feeling, the tooth is loose. Caries leads to tooth loss: low chewing function, malnutrition Caries, as well as the development of chronic apical abscess, fistula, the formation of foci, the infection can spread to other tissues or organs, such as arthritis, endocarditis, nephritis. Oral operations such as tooth extraction and periodontal scaling can cause temporary bacteremia, and in patients with organic lesions of the valves, bacterial endocarditis, and endarteritis. Studies have reported that removal of dental lesions and ocular diseases such as iritis, iridocyclitis, and retrobulbar optic neuritis can be cured. Erythema multiforme, urticaria, eczema and other skin diseases are alleviated.