Dental hygiene programs are offered at universities, community colleges, and trade schools. Any program, no matter the focus, depends on the quality of the instructors and curriculum itself. The biggest thing to look for is that the program/school is accredited. You can find a list of accredited programs here: http://www.adha.org/resources-docs/71617_Entry_Level_Schools_By_States.pdf
I would also suggest talking to the program director and asking what their Board pass rate for graduating students is. You can probably even tour the campus to compare programs.