I had a crown fitted several years ago on my lower left molar 2nd to last, I have no wisdom teeth, and now, several years later, I experience moments of pain and discomfort lasting a week to 3 weeks. I am begining to think the tooth
under my crown
has become infected as even the tooth
where the crown meets is beginning to turn black. I also get a bubble of pus on my gums under the crowned tooth that fills and fills until it bursts on its own.