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.
As of August 2004, New York and South Carolina are the only states in which dental hygienists are able to give local infiltration and not block anesthetic. Proficiency is determined by coursework during the dental hygiene program or completion of appropriate training in an accredited continuing education setting.