pain in bridge

I've had a bridge done some 10 years ago. One of the crowns is made of gold. Just last week, the area around the gold crown started to hurt. It was a consistent throbbing pain ahd the degree of pain varied throughout the day. It became worse at night. I went to see a dentist today who checked the bridge and found no breakage or any sort of symptoms to explain the cause of the pain. He then took an x-ray and again, could not see a problem. I've had a root canal on the tooth where the gold crown was put on. He advised me to be vigilant in keeping the bridge clean by flossing properly. I've just woken up from a shooting pain in the same tooth. Could you suggest possible cuases/reasons for this pain, please? Thank you.

[scottma]

If there is no structural pathology identified by a dentist, seeing an orofacial pain specialist is advised.