Clivia

I agree that it's a Clivia, just lovely.

I don't know if you're a beginner w/ plants. I haven't found these easy to grow, am trying again, but you may wish to read up on its requirements & see if you'll be able to meet them before buying one. They're not that quick to bloom either from what I've heard.

Perhaps the dentist's office where you saw it can suggest care info. & a source they used.

Yes, ask your dentist where they got it. My guess is that it came from a florist, because the conditions in the office would not be conducive to the life and flowering of clivias. But if you want to take on a big plant project, do some research, then get yourself one and have at it.

I wouldn't put to much stock in clivia cultivation advice from a dentist office and even less from the place that sold it to the office.

Yes It's a Clivia miniata as mentioned it's a big plant growing project Link to some Cliva selections