The most effective way to remove calculus is to go to the hospital for a scaling. Already formed calculus is difficult to remove completely by brushing only. Ultrasonic scaling removes calculus from the surface of the teeth by using high frequency vibrations generated by ultrasound. Patients are not recommended to remove calculus at home with their own tools for two reasons: on the one hand, improper handling may cause damage to the teeth and gums; on the other hand, there is no way to polish the teeth after removing the calculus, and the surface of the teeth will not be smooth, making it easier for soft tartar to accumulate and form new calculus. In addition, the role of scaling is not a permanent one, it is recommended that every 0.5-1 years to go to the hospital for a dental cleaning, daily brushing, after meals should also be timely rinse mouth.