Of course I can't give you all the links, as there were dozens. I suggest you Google it and do some research yourself, as you'll find there are plenty of bad stories. I have no dog in this fight, as I have no affiliation with anyone, just trying to tell others there are bad things that have happened and to be cautious. I'm glad you didn't experience them personally, and as my post said, there are plenty of happy campers, but to me the risk isn't worth it. I prefer to have a dentist locally where I can go back if I have problems, and I also prefer to use doctors who are regulated, as I said.
And an office can look immaculate but that doesn't mean they follow sanitary practices.