In many states, yes — coronal polishing is one of the expanded functions a trained dental assistant can perform, usually after earning a permit or completing a board-approved course.
It means polishing the visible crown surfaces of the teeth to remove soft plaque and stain — not scaling hardened tartar or performing a full dental cleaning, which stay with the hygienist or dentist.
Whether it's allowed, and what training it takes, depends on your state.
The short answer
Coronal polishing is one of the classic expanded functions for dental assistants, and many states allow it — but as a trained-and-permitted duty, not a basic one.
Where it's permitted, you'll typically need a board-approved course, and sometimes a permit or exam, before you may polish patients' teeth.
A handful of states don't authorize assistants to perform it at all, and the training requirement varies (Arizona, for example, requires specific training).
So the answer is "yes in many states, once you're trained" — with your state's rule as the deciding factor.
Coronal polishing is an expanded function — check your state's rule
What coronal polishing actually is
The "coronal" part refers to the crown of the tooth — the part you can see above the gumline.
Coronal polishing is the process of using a rubber cup or brush with a polishing paste to remove soft deposits and surface stain from those crown surfaces, leaving the teeth smooth and clean-looking.
It's a preventive and cosmetic step, not a treatment for disease.
In many practices it's the finishing touch on a visit — often performed after a hygienist or dentist has done the clinical work that removes hardened deposits.
Coronal polishing vs. a dental cleaning
This is the distinction that matters most, because the two are easy to confuse.
A full dental cleaning — a prophylaxis — includes scaling, which is the removal of hardened tartar (calculus) from the teeth, including below the gumline.
Scaling and root planing are the licensed clinical scope of a dental hygienist and are off-limits to assistants.
Coronal polishing is only the polishing part, on the visible crown, of soft deposits and stain.
An assistant with the right training can polish; an assistant cannot scale, diagnose gum disease, or perform the hygienist's prophylaxis.
Keeping those straight is what keeps the duty within scope.
The training or permit you need
In states that allow it, coronal polishing almost always requires a board-approved course covering technique and safety, and often a permit or a passing exam on top of it.
It's frequently bundled into expanded-function or registered-assistant credentialing rather than granted on day one.
Because it's a state credential, the specifics live with your dental board — some states fold it into an EFDA-style pathway, others treat it as a standalone permit.
For how these state permits relate to national certification, see our guide to CDA vs. RDA and the dental assistant title maze.
How the rules vary by state
The pattern is familiar from other expanded functions: most states permit coronal polishing for trained assistants, but the required course, whether a permit or exam applies, and the supervision level all differ.
Arizona is a commonly cited example of a state that requires specific training before an assistant may perform it.
A minority of states don't authorize assistants to do coronal polishing at all.
Treat any state names here as examples of the range, not a definitive list — verify the current rule for your exact state, since these requirements change.
How to confirm your state's rule
Your state dental board publishes the practice act, the list of expanded functions assistants may perform, and any course or permit each one requires.
The ADAA's state pages are a useful starting map, but the board is the authority where they differ.
Because coronal polishing sits in the state-by-state expanded-function category, confirm your state's exact requirement before enrolling in a course or offering the service.
Note the date you checked, since scope rules are periodically revised.
This article is general career information, not legal or clinical advice. Expanded-function and scope-of-practice rules vary by state and change over time — confirm current requirements with your state dental board.