Missouri and Tennessee Put Dental Board Authority Under a Microscope
State dental boards are created to protect the public, but two recent scope-of-practice disputes are forcing a sharper look at how that mandate is being interpreted. In Missouri and Tennessee, dental hygienists and professional advocates are challenging moves that would widen what dental assistants can do, with the debate centering on statutory authority, education, competency, and the boundaries between regulation and law.
The conflict is not simply about who may hold an instrument or complete a chart. It is about whether a board can enlarge a delegated function through rulemaking when the legislature has already defined where one profession ends and another begins. In oral health care, those lines matter because the tasks involved are not cosmetic extras; they directly affect diagnosis, prophylaxis, periodontal assessment, and the safety of patients whose tissue status, bleeding risk, and disease burden can shift from one visit to the next.
One sentence captures the tension: public protection and workforce convenience are not the same thing.
Missouri’s Expanded-Function Proposal Collides With Statutory Limits
Missouri became the more explicit legal battleground in September 2026, when the Missouri Dental Hygienists’ Association and former association president Lori Crawford filed suit to block a proposed rule that would create a periodontal expanded-function permit for dental assistants. The proposal would allow qualifying assistants to perform supragingival scaling and comprehensive periodontal charting under a dentist’s delegation.
The challenge rests on a straightforward statutory argument. Missouri law defines the practice of dental hygiene to include removing hard and soft deposits from teeth and performing clinical examinations of the teeth and surrounding tissues for diagnosis by a dentist. State statutes also restrict the Dental Board from issuing rules that would let dental assistants perform delegated acts that conflict with that definition, with only limited exceptions such as polishing, sealant placement, and topical fluoride application.
At the bedside, the distinction is not academic. Scaling is not a clerical function; it requires anatomical judgment, an understanding of periodontal disease, and the ability to recognize when deposits, inflammation, or tissue response move beyond routine delegation. Periodontal charting also carries clinical weight because it informs diagnosis, treatment planning, and the detection of disease progression. If a board stretches the assistant role into work that resembles hygiene practice, it risks eroding the competency standard that separates tasks assigned by custom from tasks authorized by law.
Legal review will determine whether the rule survives. The broader policy question is whether scope changes that alter the practice of a licensed profession should be made in an administrative office or in the legislature, where testimony, debate, and statutory amendment can happen in public view.
Tennessee’s Air Polishing Debate Raises a Different but Related Question
Tennessee’s dispute follows a different procedural path but lands in the same place: how far can a board go when it reinterprets an existing delegated function? At its January 2026 meeting, the Tennessee Board of Dentistry considered whether air polishing could be treated as part of coronal polishing for registered dental assistants. The discussion centered on education and competency, and the Board moved toward viewing air polishing as a type of polishing rather than a separate procedure.
The state already gives the Board authority over polishing and over the education and competency requirements tied to that function. So the issue is not whether Tennessee can regulate assistants at all. The real question is whether an administrative board can broaden an existing category to include a different technology or technique without a clear statutory foundation or a demonstrated training standard that matches the procedure’s actual demands.
Air polishing may sound like a modest variation on a familiar task, but clinical procedures are not defined by marketing language or the convenience of the operator. They are defined by tissue effects, risk profile, and the knowledge needed to use them safely. Any expansion of assistant duties should be matched to training that is specific, measurable, and documented, because patient harm rarely begins with a dramatic error. It often begins with a small mismatch between task and competence.
Access to Care Cannot Become a Shortcut Around Standards
Dental workforce shortages are real, and many communities face delays in care that are neither abstract nor rare. Rural practices, underserved urban neighborhoods, and crowded public clinics all feel the pressure when appointments are scarce and provider time is limited. Those pressures create a powerful argument for flexibility, but flexibility has to be built on evidence rather than assumption.
Dental hygienists complete accredited programs that require at least two academic years of curriculum and extensive instruction in biomedical sciences, periodontology, instrumentation, patient assessment, radiology, infection control, and supervised clinical care. Missouri law defines an accredited dental hygiene school as a program approved by the Commission on Dental Accreditation with a minimum two-year curriculum in an institution of higher education. That educational foundation is not decorative. It is the reason hygienists are trained to recognize disease patterns, manage soft tissue conditions, and perform procedures that carry both preventive and diagnostic value.
When policymakers want another category of worker to perform a procedure outside its current scope, there is a lawful path forward: introduce legislation, gather evidence, hear from dentists, hygienists, assistants, educators, patients, and public-health experts, and then decide whether the statute should change. Administrative reinterpretation may move faster, but speed is not a substitute for authority.
Patient Safety Remains the Core Regulatory Test
Dental boards do not exist to solve staffing shortages, lower labor costs, or preserve any one profession’s territory. Their duty is to the patient in the chair, which means each scope decision should begin with a hard set of questions: What education is required? What competency must be demonstrated? What procedure is being delegated? What patient safeguards are in place? And does the board have the legal power to make the change it is attempting?
Those questions become even more important when the proposed change affects periodontal care. Periodontal disease is not a superficial condition. It involves inflammation, biofilm, calculus, attachment loss, and tissue destruction that can progress silently until the damage is established. Procedures tied to diagnosis or removal of deposits must therefore be aligned with training that matches the biology of the disease, not just the workflow of the practice.
Missouri and Tennessee are not identical cases. Their statutes differ, their regulatory pathways differ, and the procedural posture of each dispute is distinct. Even so, both states are testing the same boundary: whether a dental board may quietly expand practice through interpretation when the legislature has not clearly spoken.
If the answer becomes yes, the public loses an important safeguard. If the answer remains no, boards will need to defend access solutions without drifting beyond the authority they were given in the first place.