Q. I had a porcelain crown fitted in October 08. The crown fractured at the back in April. The dentist who fitted the crown said it was not too bad and ground it smooth. Since then the crown has fractured again. It now feels waffer thin and will snap at any time. What I need to know is, am I entitled to this crown being replaced free of charge. It is a lot of money to pay and 6 month is not a long time considering they should last 10 years.