The retained root is a chronic irritant and source of inflammation, may also currently or become the source of a bacterial infection. Inflammation and infection in the jaw bone is not often apparent on a dental xray until it has become moderate or quite large. It can also be difficult to diagnose at this stage because that area of bone has not healed closed yet below the gum line and it will appear radiolucent (black), the same as an infection.

The sooner you have the root tip removed, the better.

Bryanna