This is the second crown as the first one was sent back as it did not fit. Today it was fitted and was very high so the dentist filed it down. Now there is a very visible spot several mill. in diametre of metal showing in the very centre of the crowned tooth looking like decay. The crown also does not fully cover metal exposing several mill. on the inside of the tooth. All unsightly and un cosmetic. Is this all to be expected as dentist says? What should I do as I am unhappy with the result?