After a damaged tooth is removed the 'socket' naturally produces a blood clot. Over time the gum will heal over the clot, and gum tissue is restored. However, after the tooth is removed, if the clot is lost (by premature rinsing for example) the bone can be exposed to the air and this can be very painful. An anti-bacterial swab can be inserted and slowly the gum will heal from below until the gum tissue is restored. Usually a course of anti-biotic treatment will also be required.