on and off throbing/annoying pain in lower back left root canal crown tooth

[verythirsty40]

hi i have annoying pain on and off on my back lower left tooth its not all the time it comes and goes the bite is good but sometimes i fell a little something the xrays looked good anyone have any idea what it can be thanks

 

[Zuri Barniv]

There may be a small area of excessive wear causing the inner layer (more sensitive dentin layer) to be exposed. When you happen to bite just on that spot, it hurts, otherwise it is fine.