Information about tests and licensure can be found on the University of Pittsburgh Dental Hygiene Program webpage. There is also dental hygiene program contact information.
There is information from the American Dental Association about the National Dental Hygiene Board Examination.
Clinical Examinations from the Commission on Dental Competency Assessments are required.
Licensure information is available from the American Dental Hygienists Association Licensure webpage with further links at the bottom of the page.