I have been trying to figure out if I am using the create software and how to do it. I have been trying to create a 3D tooth for a website and I am trying to make it with after effects but it isn't working. I want it to rotate on play and everything, that I can do. Though the tooth has 4 legs (stubs) at the bottom and I don't know what to use to make that concaved look for 3D; or if I should import it from like illustrator or something.
Based on your description, I'd suggest using a 3D application that can design 3D models and animate them instead of using After Effects. Cinema 4D is one of those apps and it comes bundled with After Effects.