I concur about the dental emergency kits. They've vanished.
I recently updated my kits. I had to toss my dental kits as they were about 12 years expired. Imagine trying to use the filling mixture and finding it won't cure! I replaced my kit with with a little tube of Oragel (20% benzocaine) and some Tylenol. Gauze sponges can be used to protect a damaged tooth. I did find some temporary filling kits on Amazon, but nothing suitable for stuffing into my FAK.
That nobody makes a field dental first aid kit makes me think that either the dental industry has interfered or the kits were just garbage or both.