I may be completely wrong, but I think such duties are carried out by such people in the UK at least:

What is the work like?
As a dental nurse you would provide help and support to dentists and other dental care professionals during dental appointments.

Your duties would usually include:

tidying and preparing the surgery
sterilising instruments
passing instruments to the dentist, therapist or hygienist
removing water and saliva from the patient’s mouth during treatment
preparing materials, for example, to make fillings
making sure the patient is relaxed and comfortable at all times
maintaining sterile conditions within the surgery, following health and safety guidelines
helping the dentist record information about each patient
carrying out stock control.
In general practice, your tasks may also involve working at the reception area (especially during busy periods), booking appointments, taking payments for treatment, greeting and reassuring patients.

With training and qualifications, you may be involved in monitoring patients' welfare when they are sedated
http://careersadvice.direct.gov.uk/helpwithyourcareer/jobpro...

"Junge (25 J.), engagierte **Zahnärztin** sucht zum nächstmöglichen Termin eine interessante Stelle als Vorbereitungsassistentin im Raum Mainz/Wiesbaden! Nach meinem erfolgreich absolvierten Staatsexamen an der Universität Mainz im November 2008 suche ich nun eine interessante Assistentenstelle mit möglichst breitem Behandlungsspektrum, gerne mit Chirurgie und auch KFO, um vielseitige Berufserfahrung zu sammeln und um lernen zu können.Wenn ich Ihr Interesse geweckt habe, freue ich mich auf ein persönliches Vorstellungsgespräch!"

The above (and other) job ads suggest that **full qualification** as a dentist is required.



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Note added at 19 hrs (2009-01-04 13:24:45 GMT)
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Added: Job ads for Stateside 'associate dentists' also Google well Stateside.