My dentist of the last 4 years is telling me that I need 12 crowns (6 top and 6 bottom) on my front teeth all at one time. After the last crown that he recommended was completed last year I found that my top front teeth were hurting. When I went to my last cleaning he is telling me that my bite has broken down and I need to do the 12 crowns. Is this guy just scamming me?