If the decay is not severe and the pulp is not exposed, the filling process will be quick, taking only about 0.5-1 hour of your time. Firstly, the decayed tooth around the cavity should be cleaned up and secondly, the filling should be done with special materials. The patient can eat right after the filling and there is no effect of eating. If the decay is more serious, resulting in exposed pulp or pulp infection, this case requires root canal treatment, and the filling can only be done after root canal treatment. In this case it takes a little longer. Root canal treatment requires 2-3 sessions, each about a week apart, and the whole process of root canal treatment takes about a month. However, each treatment does not take long, about an hour. Also, if the cavity is large it is not recommended to fill the tooth, and a crown is a bit more durable after root canal treatment.