The tooth is broken. The doctor said to open the tooth and see the condition of the root. Is it feasible? What are the bad consequences?

Is it painful to be blocked by food? Do you feel your teeth grow taller? If it is, it is the apical inflammation. The best method is root canal therapy. After treatment, you will almost stop eating. You won't drill many holes, but you'll be fine if you remove the materials you made before and deal with them again.