For example, a graphite/epoxy (graphite fibers suspended in an epoxy matrix) lamina may be on the order of 0.127 mm thick. For the purpose of analysis, a lamina is typically modeled as having one layer of fibers through the thickness.
Minnesota allows dental therapists with direct supervision; and advanced dental therapists (ADT) with general supervision. ADTs may be dually licensed as an ADT and registered dental hygienist (RDH). Maine allows dental hygiene therapists (DHT) with direct supervision.
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.