Upper or lower? I lost #14 to "resorption" back in '92; the dentist told me that the bone of the lower jaw is much more dense, and therefore more suitable to implants, than the upper. #14 is in the upper left rear, so I had to go with a bridge.
Upper right.
"The same tooth got a root canal twice?"
Yes, 1976, using an old method that failed.
Second time in 1991, using a new method.
Unfortunately, I still had several abycesses after that. Turns out that my body was absorbing the root tip of the one root and it kept causing abycesses. Three surgeries, the last one taking out the entire root. That was a stop gap, and the Dr. that did it told me I'd have to consider replacement alternatives sooner rather than later.
Oh, did I mention the titanium post and a second cap in 1997?
Now you know why I call it Frankentooth.