There are many ways to brush teeth, for periodontal disease patients I recommend the Bass brushing method (Bass brushing method) This method has strong cleaning power, can effectively control plaque, and can avoid causing tooth neck defects and gum recession. Bass brushing method means that the bristles are at an angle of 45° to the tooth surface when brushing the inside and outside of the teeth, with the bristle tips pointing in the direction of the gums, so that the bristles enter the gum sulcus and enter the interdental part. The bristles are pressed against the gingival margin for a short distance of anterior and posterior chattering (can imitate the vibration of an electric toothbrush or electric shaver). When brushing the chewing surface, the bristles are pressed firmly against the occlusal surface, making a short anterior and posterior flutter.