Subgingival scraping is generally harmless, but there are certain surgical risks, such as bleeding and bacteremia. 1. Bleeding: It is the most common surgical complication. Periodontitis tissues themselves have a certain degree of congestion and inflammation, which may lead to heavy bleeding after the surgery, and if the patient has a disease with coagulation disorders, the surgery is relatively risky. 2. Bacteremia: Any oral surgery may cause bacteria to temporarily enter the bloodstream and lead to bacteremia. Under normal circumstances, it is not a big problem. However, some diseases increase the risk of bacteremia and lead to other complications. Such diseases are rheumatic heart disease, arthritis, nephritis and diabetes. If necessary, oral antibiotic medications can be taken before the procedure to prevent infection. Patients with these risks should actively seek medical attention and follow up with treatment and therapy as directed by their doctor. Subgingival scraping is a form of periodontal treatment, which is not harmful in itself. Improper operation or other reasons may lead to complications, and it is recommended to consult a professional organization for treatment by professionals.