If you pull a baby tooth out, how come you don't have to do anything to the hole to keep from getting infection?

Closes itself: It will close itself up. Just like when kids loose teeth on their own.

Depth: Usually it is very shallow and less likely to collect debris and cause probs. Children also heal much faster than adults so the hole closes faster than adults.

Saliva: The saliva contains enzymes that suppress germ growth.The shallow hole is bathed by a constant flow of saliva limiting the chance anything would have to take hold. There are certainly germs that pass through, but this is rarely a problem.If it isn't broke, we shouldn't try to fix it.