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.
Align Technologies specially trains dentists to use the aligners. As of April 2007, an estimated 20,000 general dentists in the United States had trained in how to prescribe Invisalign and become certified by Align Technologies to prescribe the aligners to their patients. However, it is important to understand that a certified Invisalign dentist may not necessarily be an orthodontist.