The parents of a group of children with autism this week sued several drug companies and dental associations in the United States for allegedly exposing their kids to the neurological disorder in vaccines and dental fillings containing mercury. The American Dental Association, Georgia Dental Association and drug firms American Home Products Corp., now known as Wyeth, GlaxoSmithKline Plc., Johnson & Johnson and Armour Pharmaceutical were accused of, among other things, negligence in 11 lawsuits filed in an Atlanta court.