Hi Jellybean,
There have been no such recent changes to the use of midazolam.
Midazolam has only ever been licensed for the treatment seizures in children - however we can use it in adults "unlicensed" in the case of an emergency. It is the dentist's choice to make the decision to use an unlicensed medication and not that of your supplier. Guidelines by the UK resuscitation council still recommend the use of midazolam in adults for the treatment of seizures - i would let your supplier know this and that the dentist will be using it "off the label" as it were, or i would move to a new supplier. Another thing the dentist could do is write a private script to get it from a pharmacist.