Use your thumbs and forefingers to gently pull the floss from the gumline to the topof the tooth to scrape off plaque.
用拇指和食指沿着齿龈向牙冠方向缓和地拉扯牙线，以去除牙菌斑。
2
First, I'll make a small opening in the top (crown) of the tooth to expose the infected pulp..
首先，我要在牙齿的顶端(牙冠)开一个口，使受感染的牙髓暴露出来。
3
Due to the above mentioned defects, early fatigue peeling occurs under the condition of overly contact stress at the topof the tooth caused by abnormal contact at the tooth surface.