US class action against dentists LOS ANGELES: A class action lawsuit has been filed against dentists in the US claiming they have misled the public about the dangers of mercury in tooth fillings.   A coalition of public interest groups has sued the American Dental Association and the Californian Dental Association.   "The worst thing that they are doing is hiding the presence of mercury in fillings," said attorney Charles Brown outside the Los Angeles Superior Court yesterday.                                                                       - Darrell Giles