hey kent, will it cause problems if i just model the teeth while retopo-ing the gum?
No you can do that if you'd like. One of the benefits of duplicating teeth around is that the same texture space is used for each tooth, saving some time texturing. But if you model them individually and connected to the gums, you will have to texture them individually. That is IF you plan to texture.
BTW I love your avatar/logo.