Upper Incisors

Three different dentists have looked for the problem I describe to them and no one can see the problem (nor can I see it).  Even worse, they seem to make me feel like what I describe to them is not possible.
About three years ago the incisal edge of the upper incisors (central & lateral) started feeling worn and spongy when the lower teeth occlude with the upper.  Worse yet, there feels like the actual edge can be moved with my lower teeth and with my tongue and it is driving me nuts!  I can't go to sleep at night for running my teeth over the edge of the upper incisors and moving the loose "skin" around.... I also do this all day and night.  There is a taste associated with it.
I realize enamel is the hardest substance in the body and that this doesn't seem normal, but do you have any idea what the problem is and what can be done to correct the problem?
Merry Christmas!!
Laura

[scottma]

Your descriptions appear to suggest that upper incisors tend to move forward when you close your mouth. If the condition occured after restoration of posterior teeth , occlusal interference of posterior  restoration is probably the culprit. If front teeth have  periodontitis, periodontally compromized teeth are not strong enough to resist biting force of lower teeth.If no above condition present, it's just too much occlusal overload of front teeth. Seeing a prosthodontist to evaluate occlusion and do a fremitus test is advised.