Sucking and teeth

Je

We sleep trained my now 6 month old without using a pacifier. The last couple nights he’s started sucking on his fingers (loudly, I can hear it outside of his room lol). My question is, is it worse for his teeth to suck on his fingers than a pacifier? At this point he only has his 2 bottom teeth.

*editing to add that he isn’t sucking his thumb, it’s a couple fingers.