If they were competent, capable, respectful dentists there would be absolutely NO reason to make such a demand!
Cassandra, that is a really inflammatory, generalized statement you made there.
In my office, the *child* gets to make the decision. Some do want their parents back with them, and that's fine.
Others DO NOT, and that's okay, too. Some children like to feel like "big girls/boys", or they want to do this "by myself".