Very sore crowned tooth - please help

[preciousno1]

I started suffering from terrible toothache in a back tooth that had a deep filling on in November 2010.
In december 2010 my Second Molar on my top left side had a root canal followed by a porcelain fused to metal crown. Since then I have had a little bit of pain when I bite down on the tooth or some days it just feels sore..

The past few days it has become very sore though and I can not chew anything on that side as the tooth feels very bruised/sore.

I suffer from Bruxism but have been wearing my mouth guard as often as i can.

What do you think could be the problem for it to be so sore?. Could my procedure of somehow failed?.

Any advice or help would be great..

Regards, aimee.

[Dr Ehsan J. Esfahani]

Hi, I am sorry to hear you are suffering from this tooth again. Without seeing you for an assessment of this tooth we can't tell you for definite what the problem is but it sounds like you have a tooth or gum infection. Following root canal treatment occasionally the infection returns and the tooth feels painful or tender to bite on again. The infection can come from the tooth or from the surrounding structures. We have a 24 hour dental emergency service and one of our experienced dentists will see you. In the meantime painkillers such as ibuprofen can be taken for pain relief.