<s>[INST] i Have recently been on a very strong aniboitic and take 6 25 gm of methadextrate a week, I wear upper dentures which fit propery. I noticed a sore spot on the gum and last night when I removed my denture there was blood in it... I do use a glue and always have. How can I heal it, I have been using salt water ever hour. [/INST] Hi, Welcome to Chat Doctor, You have not written which Antibiotics you have taken. Penicillin related antibiotics can interact with Methotrexate (Methadextrate), and increase the level of Methotrexate in blood. Increase level of Methotrexate can cause side effects like decrease in White blood cells, which can cause sores in mouth. Denture can irritate the sore and can bleed. You must go and see a Doctor. He or she would examine you and may you to do blood test tor WBC count. If it is low, you may have to skip Methotrexate this week. In the future, before taking any medication, you must inform your Doctor that you are on Methotrexate. Take care. </s>