When you cut yourself, your skin will heal. Even if you sustain a serious cut that requires stitches, your skin will eventually heal and will be whole again. When a tooth gets damaged, it can not repair itself.
If you break a bone in your body, you will go to the emergency room and have a cast made to immobilize your broken limb. You may even need to have surgery to hold the broken pieces of bone together. With time and immobilization, your bone will heal and be whole again. Teeth can not do that. A broken tooth can never be whole again.
This tooth, a permanent central incisor has sustained a significant fracture. Luckily for this young patient, modern adhesive dental materials and technology enabled her dentist to bond the fragment back on, making the tooth look whole again. Her smile has been restored to look the same as before the accident. The reality is that her tooth is no longer whole and will require repeated care in her lifetime. Like all teeth that get drilled and filled, this tooth will cost a lot of money.