I believe Crown failures are common after 5 -15 years, simply because bacteria will get inside of the crown and have a field day
with your
tooth, all the while the bacteria are protected from removal, hidden by the
crown. Many Dentists does not communicate this reality when they sell you on getting the crown. An Endodontics can do the root canal without removing the crown, they just drill through the crown, do the root canal and seal entry of the crown. Hope this helps.