I agree with Eldho, and you may want to identify sections of enamel and dentin by anatomy using a scanning electron microscopy. Micro sample can then be taken of the dentin and enamel. If you do not have a SEM, samples must be teeth that were extracted and saved in preserving solution. Dried out sample will shattered and you will not be able to section the specimen. Using an electric motor at high rpm with sectioning disc will yield clean samples.
There are many different way you can you to crush the tooth, so I don't know if you are interest to separate dentin and enamel by one parts par parts. one way you can used diamond bur by removing small pieces till you reach on dentin and then after used solvent to separate dentin and enamel.