robertw,

The root canal only appeared to work for three years simply because you did not have any obvious symptoms of the chronic infection until the fistula appeared. The appearance of the fistula indicates a long standing infection as the bacteria takes times to burrow through the bone.

All root canaled teeth contain necrotic diseased nerve tissue inside of those tiny canals that I mentioned in my previous post to you. Because symptoms of a problem were non existent or delayed does not indicate that this tooth was not diseased.

The second root canal procedure temporarily reduced the inflammation as some of the decrepit tissue inside of the large canals was removed. The reason it was temporary is because the diseased tissue is still residing in those tiny canals as well as in the jaw bone along the fistula tract.

This tooth may or may not be fractured. Most of the time tooth fractures do not show on dental x-rays as they are only a 2 dimensional image. Again due to the limitations of the radiographic images some infections will not appear until they have proliferated way beyond the tooth and surrounding bone.

That small dot in the center of the tooth that is seen on the x-ray will actually be larger clinically and it indicates decay or tooth rot which has occurred from the infection. That area is no longer hard as it should be it is soft and mushy from the infection.

I know you want to believe that your tooth was okay for three years. But the truth of the matter is that tooth has been infected the entire time. We all want to go by symptoms as they are what alerts us to a problem. However, most dental problems have little to no symptoms until the problem has progressed. Similar to heart disease or diabetes.... symptoms are not always present until the disease has progressed.

I know this news is not pleasant to learn but I hope that this information has been helpful to you.

QUOTE=robertw;1077761]Thank you for your reply and information. My question is, the root canal worked for three years. Then developed a fistula. The root canal was retreated and the fistula either came back or developed a new one within 2 months. Why did the retreatment fail so soon and shows no sign of infection or fracture on x-rays? What does this indicate?[/QUOTE]