Q. I had a filling replaced on my upper right 2nd to last tooth. then had a piece of on top of the tooth fixed on the bottom left. after ward my bite was so off my front bottom teeth hit my top on the inside. went back and the dentist said it wasn’t from the work I needed a night guard. went to another dentist who said the same thing. sill don’t think they were right because my bite got worse to the point I couldn’t chew gum anymore because it bothered me so much. went back to my dentist recently and he took a drill to the back of my front teeth and shaved some off to correct it. now the back of my front teeth are very sensitive. is that normal and should that have been done. because now I am thinking he drilled off the enamel please let me know your thoughts.