I was at my dentists office and noticed they have some pretty high quality video screens there made by Sony - I was curious, is there any difference between these monitors and the ones used by editors?

We've got one of those in our studio. They're good, but not quite good enough for color correction. The resolution is lower, the colors aren't as well defined, and it isn't as easy to calibrate as a good NTSC studio monitor. It'll do well enough though, and they're a dime-a-dozen on eBay. Just don't trust that it's perfect, always re-check CCing on a real NTSC Calibrated monitor.

Medical Grade monitors are sometimes not better. They are made to not emit any noise or interfere with any other medical equipment. They have to go through lots of testing before validated as medical grade equipment.