Scope of Practice for Dental Hygienists and Supervision Levels
What this domain tests
Expect item stems that describe a clinical scenario and ask whether the hygienist may legally perform the service, and under which supervision level.
What a hygienist may do
The hygiene license covers assessment and data collection, prophylaxis, scaling and root planing, coronal polishing, topical fluoride, sealants, radiographs the dentist orders, impressions, periodontal charting, and patient education. Each service still rides on a dentist's authorization at the required supervision level.
What stays with the dentist
Diagnosis and treatment planning, prescribing, restorative and surgical procedures, prosthodontics, orthodontics, and administration of local anesthesia and sedation remain with the licensed dentist. A hygienist who tells a patient "you have periodontitis and need four quadrants of scaling" has moved from data collection into diagnosis and treatment planning.
Supervision levels
- Direct supervision: the dentist is physically present in the office, has typically examined the patient or authorized the service in advance, and is available to intervene.
- General supervision: the dentist has authorized the service, need not be present, but must be reachable and must have established the treatment plan.
- Public health or setting-specific supervision: limited settings (health departments, school programs) may operate under a written protocol; the protocol is what makes the arrangement lawful.
Delegation limits
A hygienist cannot re-delegate hygiene services to an uncertified assistant, and a dentist cannot delegate a non-delegable duty by calling it "routine." The dentist who authorizes the service owns the outcome.
Worked example
A hygienist staffs a satellite office on Saturdays. A new patient arrives with a toothache; no dentist has seen her and none is in the building. The hygienist performs a prophylaxis. Analysis: this fails general supervision. There was no dentist examination, no authorization, and no treatment plan. The prophylaxis itself is within hygiene scope, but the supervision predicate was missing, so the service was unauthorized.
Traps
- Reading general supervision as independent practice.
- Assuming a prior exam stays valid forever; authorization must match the current treatment plan.
- Letting a hygienist "diagnose to help out" when the dentist is running late.