5.1 Dental Hygiene Scope of Practice & Duties by Supervision Level
Key Takeaways
- RSA 317-A:21-c, II defines dental hygiene services to include assessments, periodontal charting, complete prophylaxis with scaling and root planing, and administering, prescribing, and dispensing fluoride supplements, topical fluoride, and chlorhexidine gluconate rinse.
- Nothing in RSA 317-A permits the independent practice of dental hygiene (RSA 317-A:21-d).
- Under general supervision, a New Hampshire hygienist may perform radiography, oral cancer screening, placement of prescribed periodontal antimicrobials, and application of silver diamine fluoride (Den 405.01(a)).
- Hygienist duties such as placing retraction cord, brush biopsies, cytological smears, final impressions, and local anesthesia require direct supervision (Den 405.01(c)).
- In-office tooth whitening by a hygienist is performed under general supervision (Den 405.01(b); Den 302.05(q)).
Dental Hygiene Scope and Duties
Statutory definition — RSA 317-A:21-c
A person practices dental hygiene if he or she performs any act in RSA 317-A:21-c, II, or uses "registered dental hygienist," "R.D.H.," or any similar designation (RSA 317-A:21-c, I). Dental hygiene services include:
| Paragraph | Service |
|---|---|
| (a) | Assessing medical and dental histories, including preliminary inspection of the oral cavity and surrounding structures, and periodontal charting |
| (b) | Assessing the patient to collect and evaluate complete data identifying dental hygiene care needs |
| (c) | Complete prophylaxis: removing calcified deposits, excess cements, excess orthodontic bonding material, accretions, and stains from supragingival and subgingival surfaces by scaling, root planing, and polishing |
| (d) | Procedures requiring additional education and other procedures authorized by Board rule |
| (e) | Local anesthesia, if the Board qualifies the hygienist after training and an approved exam |
| (f) | Nitrous oxide/oxygen minimal sedation (anxiolysis), if qualified by the Board after training and an approved exam |
| (g) | Administering, prescribing, and dispensing a fluoride supplement, topically applied fluoride, and chlorhexidine gluconate oral rinse |
Three limits frame the whole list:
- Supervision: hygiene services are provided under the supervision of a licensed dentist in accordance with Board rules (RSA 317-A:21-c, III).
- No independent practice: nothing in RSA 317-A permits hygienists to practice independently (RSA 317-A:21-d). The Dental Hygienists Committee statute repeats that it does not authorize independent practice (RSA 317-A:2-a, IV).
- Charitable trust clinics: hygiene under a health care charitable trust is performed by licensed hygienists under a licensed dentist's supervision. The trust notifies OPLC of the clinic and supervising dentist and reports any change of supervising dentist within 10 days (RSA 317-A:21-c, IV).
Duties under general supervision — Den 405.01(a)–(b)
With the dentist's authorization and treatment plan and the 12-month personal evaluation (section 4.1), a hygienist may:
- perform all dental assistant duties in Den 404.01 and all CDA and graduate assistant duties in Den 404.02;
- perform a complete oral prophylaxis, including removing subgingival biofilm, its by-products, and biofilm-retentive calculus by debridement, scaling, and root planing;
- collect and assess medical and dental histories, including documenting systemic conditions;
- perform extraoral and intraoral assessment, including oral cancer screening;
- assess hard tissue, periodontal structures, and occlusion, documenting all findings;
- record all assessment findings relevant to dental hygiene care;
- perform dental radiography;
- collect comprehensive patient data on physical and oral health status;
- analyze the data and determine the dental hygiene treatment needs the hygienist is qualified and licensed to treat;
- establish, implement, and evaluate a dental hygiene care plan;
- place prescribed periodontal antimicrobial agents;
- apply topical preventive and anesthetic agents, including silver diamine fluoride;
- administer, prescribe, and dispense fluoride supplements, topical fluoride, and chlorhexidine rinse;
- perform in-office tooth whitening (Den 405.01(b)).
Sealants are placed under general or public health supervision (Den 302.05(h)).
Duties under direct supervision — Den 405.01(c)
| Restorative and prosthetic support | Diagnostic adjuncts | Qualified-only duties (Den 302.05) |
|---|---|---|
| Remove excess restorative material beyond the preparation margins, including with a low-speed handpiece if necessary | Make cytological smears | Orthodontic duties |
| Place retraction cord | Perform brush biopsies | Fabricate provisional crowns and bridges |
| Place and remove periodontal dressings | Administer local anesthesia | |
| Place temporary restorations, but not temporary crowns or bridges unless qualified | Monitor nitrous oxide inhalation | |
| Make final impressions | Administer nitrous oxide | |
| Place amalgam before the dentist condenses it | ||
| Place cavity liners and bases | ||
| Remove temporary restorations, without rotary instruments | ||
| Cement bands and bond brackets |
Duties under public health supervision — Den 405.01(d)
In schools, hospitals, other institutions, and for homebound persons, a hygienist may:
- collect and assess histories, including preliminary inspection, periodontal probing, and charting;
- perform complete oral prophylaxis;
- administer, prescribe, and dispense fluorides and chlorhexidine;
- instruct in oral hygiene;
- run fluoride rinse programs;
- place sealants;
- make, fabricate, and deliver athletic mouthguards.
Section 5.4 covers the program rules and the CPHDH credential.
Assessment is not diagnosis
The hygienist's authority to "determine the patient's dental hygiene treatment needs" and to "establish a dental hygiene care plan" (Den 405.01(a)(11)–(12)) is limited to conditions a dental hygienist is qualified and licensed to treat. Diagnosis and treatment planning of dental disease remain non-delegable dentist functions under RSA 317-A:23, I(a). If a hygienist's oral cancer screening finds a suspicious lesion, the hygienist documents it and the dentist diagnoses and decides treatment. The hygienist may perform a brush biopsy, but only under direct supervision.
Worked scenario
On a Friday afternoon with the dentist away, Chris, RDH, sees three patients the dentist examined within the past year:
- Scaling and root planing with placement of a prescribed local antimicrobial: lawful under general supervision (405.01(a)(2), (14)).
- Silver diamine fluoride on an arrested lesion the dentist charted: lawful under general supervision (405.01(a)(15)).
- A final impression for a night guard: not lawful without the dentist in the office. Final impressions by hygienists are a direct-supervision duty (405.01(c)(7)).
The supervising dentist is away from the office. Which duty may a dental hygienist perform for a patient the dentist personally evaluated eight months ago?
A licensed dental hygienist wants to open her own office, hire staff, and treat patients without any supervising dentist. How does RSA 317-A treat this plan?
Which statement correctly describes the relationship between a hygienist's dental hygiene care plan and a dentist's diagnosis under New Hampshire law?