unexplained enamel defect?

[btaft]

So basically three of my teeth have spots almost below the gum line where the outer enamel has completely disintegrated. The tooth itself is perfectly healthy and nothing shows on the x-rays. In my opinion it's clearly some type of hole because I can put my fingernail in it, but it's extremely painful. It's especially painful to sugar. I have seen three dentists now that have not been able to tell me what it is. One says they are not cavities just "sensitive spots". Another says an "enamel defect". Since they are very painful even when hit with a toothbrush the last dentist offered to put a small filling over them. this hasn't worked. ANY thoughts at this point would be helpful!

[Jerome Tsang, DDS]

It works almost the same as a filling except its a thin layer that covers the tubules of your roots to prevent sensitivity.  Basically the theory behind sensitivity of the root is that these tubules contain liquid and when something cold or air brushes against it, it pushes back against the pulp of the tooth where the nerve is and makes the nerve say OUCH.

You may want to re-try the fillings again or apply some dentin desensitizer around the margins to possibly seal it.

[btaft]

It has been a month or so since we have tried the fillings. My best guess is that the filling only covered what is above the gumline and whats hurting must be below just below. What exactly is a dentin desensitizer?

[Jerome Tsang, DDS]

So placing a filling hasn't help with the pain at all?  I would recommend trying some sensitivity toothpaste (it does take 4 weeks or so to work) and perhaps placement of a dentin desensitizer through your doctor.  I would still think that the filling would be a more drastic approach and should resolve the issue.  

How long has it been since the fillings were placed?  Has it improved at all?