Is getting a crown at a young age a good idea on your front teeth? (photo)

So basicly in 19 and two teeth at the front that are going slightly darker, I hate it when I smile , i had an absist, a infection in my gum that over time has discoloured two teeth,I've had the problem sorted but the teeth are dead, my dentist have told me I can have a crown on both theses teeth but I'm worried,will they look real,there going to be at the front what if they fall out. I need some reassurance from people who had the same problem?