Why didn't the target organizations of these regulations lobby the OSHA/State government to prevent this regulation. If it's that easy to get your way through lobbying I'd wager that your dentist, along with a few colleagues, could have stopped it.
They probably had no idea about it. If they did, they probably had fewer resources to throw at a single issue than would a large corporation that's going to make a lot of money from it. Also, as a politician, it's easier to justify regulation as "making sure the public is safe" but harder to justify deregulation because that requires playing not to people's insecurities but their sense of justice.