I do not feel that dental assisstant II should be allowed to scale at anytime.  I have now seen first hand how knowledgeable a dental hygienist  is, and I do not feel an assisstant could ever care for their patients in such a way.  The education that a hygienist recieves is astounding and allows us to treat the patient completely by knowing so much about the body and making connections to the patients health from the mouth.  We as hygienist can take care of the patient as a whole not just scaling.  Without this extensive training the assisstants can never provide such care for the patient.