No, they have no usage. I couldn't sell my Organic text at the end of the course b/c they changed the edition. I haven't touched it since. Now it's only good for a very heavy bookend. General bio I sold as soon as possible and I have never missed it. Same goes for Physics and General Chem. I did look at the Biochem text a little when I was studying for boards. But I could have just looked in my dental school biochem book if I wanted. Unless you have books from undergrad subjects that you are taking again in dental school (Physio, gross anatomy, histo, biochem, micro, pathology, neuroanatomy) don't bother keeping them. Even these are of questionable value b/c you may use a different text or a graduate level text rather than the undergrad level text. You'll never look up a Grignard reaction or solve a derivative again.