Q. I had gum contouring done 3 weeks ago. On Friday (3 days ago), my dentist relined my temporary to add more acrylic along the gum margin where tooth was exposed. He tried to adjust the tooth (which had been root canaled) and the bur hit the tooth. After that, he applied bonding material to the tooth before replacing the temporary. Now the tooth is sensitive. He inserted the cord on gum when he relined the temporary. Could the sensitivity be from the gum tissue? If a tooth that had been root canaled crack, will it be sensitive? I am afraid to ask him but I hope it did not crack.