This second practice is modeled on official dental assisting exams set by the national certification board, Dental Assisting National Board (DANB), and the state dental assisting association, where offered. The former credential is the Certified Dental Assistant (CDA) and the latter is the Registered Dental Assistant (RDA). The CDA Exam consists of questions in three categories: general chairside (GC), radiation health and safety (RHS), and infection control (ICE). The RDA Exam consists of two parts: the written exam and the practical. Note that the practical aspects of the exam are not covered here. This practice is a hybrid that covers material common to both exams.