Can it hurt to get cavities filled?

Usually no: It usually requires a shot of local anesthetic but not all people require this. For about 10% of the population little discomfort is felt even without a shot. Some teeth are more difficult to get numb than others. For patients that have never had a cavity filled and all things being equal, i like to start with an upper bicuspid first as it is the easiest area to treat for the patient.

No: Your dentist will give you an injection of a novocain (procaine) anesthetic type product that will cause the area to be numb, you will feel nothing.