It is not scientific to say that dentists do not recommend teeth cleaning. It is generally recommended that teeth should be cleaned every six months to a year. Do not recommend scaling is for some people, such as the following categories of people, the doctor will not recommend or temporarily do not recommend scaling. 1. Suffering from bleeding disorders: dental scaling may lead to bleeding gums, so patients suffering from thrombocytopenia, coagulation disorders and other diseases should take drugs to promote blood clotting before scaling to prevent bleeding during scaling. 2. At the onset of oral inflammation: if the patient has various types of oral inflammation or gums, wisdom teeth are inflamed, then need to wait for anti-inflammatory before scaling, to avoid inflammation along the blood dissemination. 3. Suffering from serious cardiovascular disease: if the patient has active angina, myocardial infarction within six months or cannot effectively control high blood pressure, etc., it is not suitable to receive routine scaling. 4. Have a pacemaker in the body: ultrasonic scaling may interfere with the work of the pacemaker, so it can not be ultrasonic scaling.