It would help to know what resolution you need, which teeth you're interested in, what their planned use is (teaching, research) and that you have ethics approval for this use of teeth from your institution.
Hi Rita and thanks for your reply. I need the microct for personal project and not for my institution. I need the images to obtain 3D models of teeth for surgery training and simulations! What do you mean with "ethics approval for this use"? the microct files must be anonymized obviously!
We need to have ethics approval for projects like this to comply with various requirements, even though the data are anonymised. There is a root canal project website that, as part of root canal morphology, has axial slices of tooth microCTs: that might suit your needs in the first instance? It's here: http://rootcanalanatomy.blogspot.com.au/search/label/Axial%20Sections