Does filling or extracting teeth affect the validity of fasting?

Question: If a person experiences pain in his teeth, consults a doctor, and the doctor performs a cleaning, filling, or extraction of one of his teeth, does that affect his fast? And if the doctor gives him an injection to numb his tooth, does that have any effect on the fast?

Answer: What was mentioned in the question has no effect on the validity of the fast; rather, it is excused. He must be careful not to swallow any of the medicine or blood. Likewise, the injection mentioned has no effect on the validity of the fast, because it is not in the meaning of eating or drinking. The original ruling is that the fast is valid and sound.