How long do the ceramic cap on teeth last?

My upper two front teeth are worn out. I tried Veener filling LC but it did not work. Now my dentist has put a ceramic crown/cap on them. How long will this last? During the fixing of the cap, the teeth were ground and made flat to receive crown cap. Will my original teeth become weak due to grinding and thinning? If this cap breaks will my original teeth also break? How to tackle this if the original teeth break along with crown/cap? I am scared in eating fruits even though I am taking care. Please advise.