Scope of Practice for Dental Hygienists
Scope of practice defines what a hygienist may lawfully do and under what conditions. The statute and board rules set the outer boundary; the supervising dentist's treatment plan and delegation set the inner boundary. A procedure can be within the hygienist's scope yet still unlawful if it was not properly delegated or supervised. Questions love this two-step analysis.
Know the core services: assessment, dental hygiene diagnosis within the hygiene scope, scaling and root planing, polishing, fluoride and sealant application, radiographs, and patient education. Understand which services require additional certification - local anesthesia, nitrous oxide-oxygen sedation, and in some jurisdictions expanded functions such as restorations or periodontal maintenance beyond a defined interval. Be able to state the education and examination prerequisites for those permits.
Understand the limits: a hygienist does not diagnose dental disease for the dentist, does not prescribe, and does not perform procedures reserved to the dentist unless a specific rule authorizes delegation. Know how self-initiated care or public health settings may expand independent action, and the conditions attached (screening, referral, documentation, and follow-up).
Traps: assuming anything a dentist may delegate is automatically within hygiene scope; assuming a certificate from another state transfers automatically; and forgetting that documentation and referral obligations attach to expanded functions.
Rule of thumb: ask two questions in order - is it in the hygiene scope, and was it properly delegated and supervised? Both must be yes.