Dentist question: cracked tooth...?

Question

I had a root canal in one of my front teeth and before he had put on the crown, my dentist filed both teeth to become smooth. On the tooth next to the root canal, a small dent developed. It has become sensitive. I asked my dentist and he said that he couldn't see anything, teeth aren't always smooth at the back, and since I had a previous cavity ( which was nowhere near the back of my front tooth) I might need another root canal. The indent was not something I had had before the filing. How do I show them the crack? It's vertical.

Answer 1

Tell them to take an xray