Can you tell me how to get rid of a mouth ulcer?

Gargle and avoid...: Since you mouth is teeming with bacteria, and the sore is the result of a herpes reactivation to due the virus perceiving stress: 1. Reduce the bruden of bacteria near the wound by gargling with listerine or salt water 60seconds twice a day until the sores go away (the bacterial load near the sore may delay healing), and 2. Avoid sour, citrus, acidic, spicey foods which will irritate the sore.

Depends: Without seeing the ulcer i can't really help. It could be anything from a cheek bite to cancer. If it isn't going away (within 7-10 days) or is larger than a pencil eraser then i would recommend being seen by a dentist.