Expanded Function Dental Auxiliaries (EFDAs) vs. Register Dental Hygienists (RDHs): What Can Each Do in Washington State

By Hollie H. Reese, RDH

(All information in this article was obtained from the Washington State Department of Health website.)

For a detailed comparison of duties a dentist may delegate to dental hygienists, EFDAs, and dental assistants, check out this helpful delegation chart which outlines tasks that can be performed under close supervision or general supervision.

Let’s start by reviewing the key definitions of “close supervision” and “general supervision.”

General supervision means a supervising dentist has examined and diagnosed the patient and provided subsequent instructions to be performed by the assistive personnel but does not require that the dentist be physically present in the treatment facility.

Close supervision means that a supervising dentist whose patient is being treated has personally diagnosed the condition to be treated and has personally authorized the procedures to be performed. The supervising dentist is continuously on-site and physically present in the treatment facility while the procedures are performed by the assistive personnel and capable of responding immediately in the event of an emergency. Close supervision does not require a supervising dentist to be physically present in the operatory.

What Can EFDAs Do?

EFDAs can perform all tasks of a dental assistant. In addition, they are allowed to:

Under General Supervision of a Dentist:

• Perform coronal polishing
• Give fluoride treatment
• Apply sealants
• Place dental X-ray film and expose and develop film
• Give patients oral health instructions

Under Close Supervision of a Dentist:

• Place and carve direct restorations
• Take final impressions

For a complete list of allowable EFDA duties, refer to WAC 246-817-525.

How Are EFDAs Different from Dental Hygienists?

EFDAs and dental hygienists have different licensing requirements and different scopes of practice.

In Washington, a licensed dental hygienist may:

• Remove deposits and stains from the surfaces of the teeth
• Apply topical preventive or prophylactic agents
• Polish and smooth restorations
• Perform root planning and soft tissue curettage
• Perform other dental operations and services delegated by a licensed dentist

For the full scope of what a dental hygienist can do under general supervision, see WAC 246-817-550. For tasks allowed under close supervision, refer to WAC 246-817-560.,

Final Notes

The licensing and scope of practice for EFDAs and dental hygienists are defined by different laws and regulations, including RCW 18.29.050, WAC 246-817-550, WAC 246-817-560, and WAC 246-817-570. These rules ensure each professional works withing their training and expertise to provide safe, effective care.