They were putting a new filling in where an old one had popped out. Top right incisor, tip of the tooth, back side - around 2010 a divot popped out / broke off. They warned me at the time that it was likely to be more or less temporary, but it was driving me nuts running my tongue over it.

Most of that filling popped out a month or so ago - that's what they replaced. They were rather surprised how long it had lasted.