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

2 years ago I had an Emax A1 HT inlay placed in the upper right second molar. In the past few weeks only I have been getting a dull light pain after chewing - tooth is not sensitive to hot or cold. Is it likely that the dull pain is due to a slightly high bite? Also, the surface of the Emax inlay has recently become very rough to the tongue (and slightly more yellow). Can this be re-polished using air abrasion or does polishing Emax intraorally require specialist tools and materials? Thanks.