Q. I am about to have a crown replaced. the preparatory work has been done. Initially my dentisit said i could have a porcelain crown ..it is the last but one bottom tooth .. i have had my wisdom teeth removed.When he had prepared it adn i mentione dthe porcelain crown he said he had prepared for a gold crown .. that he CIULD prep for a porcelain but it would invlove more destruction of the tooth and i could have a metal base with a white covering ..to which i agreed ..but having thought about it psoke to him again becasue i wasnt sure about the appearance of this tooth . At which point he said this was the best chioce and that we were lucky to have been able to have a second bit e of the cherry in replacing the crown. He had not mentioned this before. So the new metal base crown is due to be fitted on Monday .I am hoping it will beok ..i spoke to a freind who had some and he was happy wiht his. meanwhile part of a large filling in the back tooth next to it ..the last one .. has chipped .. Would a porcelain onlay or crown be suitable for this tooth in theory??? Last time he repaired a back filling ( large one ) he saaid only amalgam was suitable . I am quite anxious to not have any more mercury in my mouth and i do not like the appearance even on back teeth.