I've removed an entire big toenail before, when it was ingrowing. It was...uncomfortable.
Possibly the infection had partly pushed the nail off.
On the topic of dentists, my one was quite happy to have me wearing headphones while he drilled away (How fjoerken wrong does that sound??)
If you're nervous - say so. Most dentists will understand and help.
I can now have root canal treatment without embedding my fingers in the armrests.
Mostly.