Not really sure how decay can build up beneath a crown on a root-canalled tooth, but it can. Or, I should say, my teeth are capable of it. If you took all the dental work I've had done and totalled up the amount paid and took that amount to a Honda dealer, methinks you could walk out with a basic Honda Civic DX.
I have a car in my mouth.
Pardon me while I rest and eat soft foods and grumble today.
And, no, I did NOT eat too much cotton candy. I've been very good.