As a dental hygiene student, I'm in a very rigorous program of pre-clinical and clinical studies to understand fundamental concepts of oral health as well as to learn the necessary technical skills to perform my duties safely and efficiently. Patient treatment and safety should come above everything else.  Dental hygienists are thoroughly educated in not just scaling techniques, but in all aspects of patient care, and  it is simply not safe to allow a DA, with little or no formal education in oral healthcare, to assume these responsibilities.