I recently had two veneers placed on my top front teeth, and now my teeth look like two chiclets placed amongst the others. The shade is completely off, much too white. The thing is, the dentist showed me the veneers before they were cemented on and the shade seemed to match. What could have happened to make the veneer look so white once placed? Does the cement placed underneath affect the shade of the veneers? They seemed to match well and now they are so white and fake looking. Help! Options?