Only if your friend is on benefits or a student, they can apply for a HC2 form, which gives them a discount...but other than that, I'm afraid they will have to pay up.
Your friend could always go to the university dentist hopsital, where they do treatment either free or at reduced cost....but if they are scared stiff then I wouldn't advise it...plus it's a long wait mind!!!
Don't go the Hospital if you have a fear of dentists! I know they've got to train on somebody, but a qualified dentist can be scary enough, never mind a group of students...