Emax inlay feels rough after 2 years with recent dull pain after chewing. How often should it be polished intraorally? (Photos)

Sounds like the inlay may be fractured.  I would suggest going back to the same dentist and seeing if s/he can examine the inlay.  If you were my patient and you fractured an inlay within only 2 or 3 years, I would replace it for free.  However, every office is different and you cannot expect every doctor to have the same polices.  I hope this helps some.  Follow me on RealSelf for more answers.

It is unlikely that the surface of an Emax restoration will become rough from normal wear and tear, and even if it did, that would not explain the dull pain. If the bite was high, you would have noticed it soon after the placement of the inlay. What may have happened is that there was a fracture at the margins and possibly loosening of the inlay. As far as discoloration, surface staining may have occurred and polishing by your dentist will alleviate this. See your dentist as soon as possible for a proper evaluation. Best wishes!