For the time of filling, usually, the time needed for filling is slightly different according to the depth of the cavity: in the first case, the cavity is very shallow, only the surface layer of enamel is defective, the filling time can be finished in about 10 minutes. In the second case, the cavity reaches the middle layer of dentin, the patient will have some symptoms of hot and cold sensitivity, but there is no continuous pain, in this case, the doctor may take some measures in the process of decay removal, the filling needs to be bedded when filling, the filling time is about half an hour. In the third case, the depth of the affected tooth is very deep, close to the nerve or very close to the nerve, in this case the filling is a little more complicated, and some treatment may be needed to protect the nerve, the filling time is about 40 minutes.