I had a dentist once tell me they needed to graft my entire gumline with bovine tissue. Never been mentioned since, so I explicitly ask now and there's been no more concerns.
I had a root canal done on a molar when I was ~16 that a dentist in basic training said needed re-done, because it wasn't done correctly. At a different duty station a couple of years later it was required that it me redone again because it wasn't done correctly the second time. Years later a civilian dentist wanted to re-do it again, because it apparently wasn't done correctly the third time. I had never had any problems whatsoever with the tooth since the first root canal.
I had a root canal done on a molar when I was ~16 that a dentist in basic training said needed re-done, because it wasn't done correctly. At a different duty station a couple of years later it was required that it me redone again because it wasn't done correctly the second time. Years later a civilian dentist wanted to re-do it again, because it apparently wasn't done correctly the third time. I had never had any problems whatsoever with the tooth since the first root canal.