Hi
Today my ds aged 8 lost his first upper lateral incisor. It's been wobbly for ages so he is super happy it is finally out. However when I've looked at it I think it is rotten inside? There is the usual nerve section in the middle which is red but then behind it is a large black area (see photo attached -this is the top view so looking down at the root etc). This wasn't visible from inside his mouth at all so isn't on any surface of the tooth but is all internal to his tooth. How would that even happen? He goes to the dentist every 6 months and has no issues. Is this something that I should be concerned about?
P.s. Please ignore the green on his tooth - he was eating spinach pasta as it fell out!