If you have a lot of dental work your likely flooded with toxins and that much Iodine forces out even more than your body can deal with it.
In addition to Iodine support supplements you should be taking vitamin C to bowel tolerance, glutathione precursors and perhaps even a hefty dose of a detox agent like 15g of pectasol.
Some practitioners blame dental health, especially root canals and abscesses as major factors in declining health because it literally wipes out all the bodies antioxidant.