<s>[INST] HI, Doctor, I had gum swelling. The local dentist suggest me some medicines and a tube gel named "Metrogyl DG Gel forte". It is written on its cover that it is for external use. Now i would like to know where should i apply this. Inside the mouth on affected (swell) area or outside the mouth around that area? [/INST] Thanks for your query, I have gone through your query. The swollen gum can be because of the gum infection or tooth infection. So applying metronidazole alone will not help. There are gels which are available for oral application. The oral application is available as gels, but skin applications are available as pastes. So consult an oral physician and get a radiograph done to confirm the diagnosis. If is a tooth infection, get the tooth root canal treated. If it is a gum infection, then get a scaling and root planing done. Meanwhile, you can take a course of antibiotics like combination of amoxicillin and metronidazole. I hope my answer will help you, take care. </s>