There is significant evidence that Crohn's disease is caused by Mercury poisoning resulting from the slow disintegration of dental fillings. The mercury release from fillings is absorbed primarily as highly toxic elemental mercury vapor. Anyone with Crohn's, Colitis, or IBS should review their dental history and seriously consider immediate removal of their amalgam fillings.
Most people born before 1975 have silver-murcury fillings, and by most I mean probably in the high 80% range. Personally I had 4 Silver-Mercury fillings. Only a tiny portion of the population suffers from Crohns disease. It could certainly be an agrivation for the disorder. Toxins in your system are bad for you in a miriad of ways but it cannot be said to be a cause based on the information linked.
Mercury dental fillings are extremely dangerous. Just look at the chronic healthcare issues of the general population. Mercury can be traced to the root cause of most healthcare issues today.
For Crohn's disease it is probably caused by the mercury in the body being mobililzed into the liver, where it then courses through the intestines with the bile. The bile has a 95% uptake, so the mercury will reek havoc on them. To detox of mercury the dental amalgams must be removed from the mouth. In all cases, with or without amalgams, developing healthy gut flora in the intestines is of the utmost importance, although if the bile is really toxic it may be near impossible to accomplish.