The Costco Gas Station hours are usually longer than the Costco Warehouse opening hours, so make sure that you are viewing the Costco Gas Station hours, and not the Store Hours, if you search through an app or with google maps.
All dental hygienists in the United States must be licensed by the state in which they practice, after completing a minimum of two years of school and passing a written board as well as a clinical board exam. State requirements vary by state, and are controlled by state dental boards.
Licensure is granted by each individual state. Dental hygienists practice in accordance with requirements of individual state dental practice acts. In virtually every state, several steps are required before a license can be granted: Graduation from an accredited dental hygiene program.