I'm gunna ask my dentist if he knows of any good / cheap clinics in the area. -- But here's some info about some clinics/dentists in the area:
I've been reading around, a few sites suggest trying to go to a college that has people being trained to become hygienists; it may possibly be free or very cheap.
I looked up schools on http://www.collegeview.com and the following are some of the schools that train for dentistry in NY:
-SUNY Farmingdale, (Farmingdale)
-Monroe CC (Rochester)
-Stonybrook U, (Stony Brook)
-Hofstra, (Hempstead)
There are 41 schools altogether in the search, but most are out of the way. (You can go to collegeview.com and do an advanced searched, if you're still interested though)
[Copying & Pasting]:
Columbia University College of Dental Medicine
Vanderbilt Clinic
622 West 168th Street
212-305-6726
http://dental.columbia.edu/
New York University College of Dentistry
345 East 24th Street
212-998-9800
http://www.nyu.edu/dental/
State University of New York at Buffalo School of Dental Medicine
325 Squire Hall
3435 Main Street
716-829-2821
http://www.sdm.buffalo.edu
Stony Brook School of Dental Medicine
631-632-8989
http://www.hsc.stonybrook.edu/dental