I just paid for several implants, the majority were fine but two of them came back from the lab with the inner metal showing through the crown restoration. I asked the dentist why it was like that, he brushed it off saying that they would cover it with composite. The others weren't like that. Now that they filled it in with the composite it looks yellow compared to the white of the crown, and i imagine will only get darker with time. I feel they should replace the crowns. I am not happy. what opinion do you have?