Q. Hi Mr Moore, I have a porcelain crown as one of my front teeth it is on a metal post,I have a very bad habit of grinding and clenching my teeth(I even clench my teeth when I fall asleep on the sofa,cinema,ect). This has resulted in me gainiCrown ng super developed muscles in my jaw,braking off bits of teeth but more importantly I believe it is through this I have pushed my crown forward, even though I wear a hard guard in the night. A few months ago I noticed what I would describe as a blood blister above the tooth, when I applied pressure it bled,more recently the blister has moved up my gum, along the line of the root. I have visited a dentist who x-rayed my teeth and gums he could find nothing but as I can feel some sort of mild pressure, but no pain, am frightened of biting into food. The dentist who replaced the crown around 4 years ago did dislodge the post and replaced it free of charge. Please can you shed any light on my problem. Kind regards,