Heloo sir. If one of your teeth
has turned black. The possible reason is tooth
necrosis. Ie destruction of the normal blood flow to the tooth which results in blackish appearance of tooth with time. Mostly caused by trauma. But in some cases infection
to the ttoth can also result in same. So treatmen t for this is. Root canal treatment
followed by non vital bleaching
procedure or rct + cap
wish you best.