I had a zirconium 3D cantilever bridge fitted 6 months ago and it has already darkened. When it was first placed it was a shade darker than my natural teeth as the dentist told me it would look more natural. He is the dentist so I did what he said. Now it is 2-3 shades darker and extremely noticeable. Can this be fixed? Can I have it remade without paying the whole amount again?