tooth sensetive to hot things

Hi, since two days ago, there is a sharp pain  in the lower right area whenever I eat or drink something hot but I can't really locate it, I felt a dull pain months ago in this area when chewing but it wasn't annoying. Cold water seems to relieve the pain quickly. I got large fillings on first and second Molar in the lower right area about 4 years ago. and there is nothing on X-rays no cavaties or anything else.

[Jerome Tsang, DDS]

Cold water relieves your pain?  Thats a worrisome sign.  You may need a root canal on one of the teeth back there in the area.  

What may have happened is that the deep cavity in the tooth either got into the tooth and infected it and gradually killed the nerve off inside the tooth, a problem with the filling, or due to the filling of the tooth, the trauma to it has caused the pulp to degenerate and die off.  In any case, the bacteria inside the tooth is now spread pretty far around the tooth and its producing a gas as a byproduct. As that gas builds up, it creates pain and pressure inside the tooth which worsens with hot liquids as the heat contributes more energy to the area and makes the gas inside the tooth push out more.  As the cold water hits it, it lowers the amount of energy and causes the gases to slow down their movement and push out less.  That's what I'm thinking is happening to you.