Cut lip on my 5.5 month

Eliana

My baby has had an open cup on her lip for about a week now it does not seem to be healing what is something I can use that’s safe for her to put in her mouth if she licks off whatever I put on?! I just don’t want it to get infected at all I’m worried

It’s on the top of her lip I tried to get a picture this is the best one I could possibly get lol.