After the dentist placed a CEREC crown on my back molar 6 months ago, I have returned to their office 5 times for bite adjustments. The crown still feels large in my mouth. It rubs against my cheek, and my bite feels uneven. Since it hurts to bite down, I sought out a second opinion. At the second dentist's office I had an x-ray done. The second dentist filed down my crown some more. My crown is still not comfortable. My bite feels weird. What could be wrong? The adjustments are not helping.