Final answer:
A registered hygienist extended functions (RDH-EF) can apply etch under either general supervision or direct supervision.
Step-by-step explanation:
A registered hygienist extended functions (RDH-EF) can apply etch under either general supervision or direct supervision.
General supervision means that the RDH-EF is performing the task within the guidelines and protocols set by a dentist, but the dentist does not need to be present in the same room.
Direct supervision means that the RDH-EF is performing the task under the immediate presence and guidance of a dentist.