Allowing dental assistants to scale teeth, even if it is only 3mm, is wrong and a disservice to patients!  I am a very qualified dental assistant and I love the work I do and the care I help my doctor give her patients.  But please don't put ME in an uncomfortable position!  I would NOT be doing patients a service.  I would be compromising their dental care.  AND I WILL NOT DO IT!!!!!!  I am not qualified to do the job of a hygienist.  Dentists don't even get as much training in regards to scaling teeth as a hygienist when they are in school.  So how can dental assistants be expected to give the proper standard of care without proper training?  Dental hygienists are good at what they do and allowing a "DA II" to scale teeth would be a slap in the face at their profession.  They train hard for 2-4 years to become hygienists and no part of their profession should be taken away.  They know what they are doing when scaling teeth.  Dental assistants...not so much.  I love what I do and subgingivally scaling teeth is not, and nor should it ever be, part of my job description.