Hello, Thanks for consulting HCM Read your query as you feel sore gum around one tooth this can be due to some reason like inflammation of gingiva due to gingivitis , periodontal problem causing pocket formation causing localized periodontitis or due to formation of gingival or periodonatal abscess . For this I will advise you to consult oral surgeon for examination of gum and investigations iopa xray to rule out the cause . Inmeantime I will suggest to do these remedies like do warm saline rinaes 2 -3 times a day , you can apply gum paint like stolin on inflamed gum , maintain proper oral hygiene , use mouthwash chlorhexidine regularly . Hope this will help you.