I am strongly opposed to dental assistants scaling patients without thehigh degree of education and supervision that hygienist have recieved.  I had an assistant come to me the other day and expressed concern that a patients poor hygiene required her to scale.  The assistant thought that just because the patient had alot of plaque that this required scaling.  I had to inform her that plaque was not something that needed to be scaled. She was truly surprised. With that said..I wonder how many other assistants are as "under-educated" as she was.