Please, when you get your second opinion, don't tell him about what your first Dr. said and for goodness sake he needs to show you the x-rays. My Dr. alway's comes in the room, looks at the x-rays, checks my teeth and gums, then shows me on the x-ray where the problem lies and then points to it in my mouth with that probe thingy and usually I can feel what he found.
Depending on the second Dr's results, I would go back to the first Dr. and have them show you the x-rays and compare the new to the old. You should be able to see if they match or not. Then confront the Dr. if things don't add up.