Final answer:
Registered Dental Hygienists can place medicaments that do not need to be removed under either general or direct supervision. General supervision does not require the dentist's presence, while direct supervision does. The RDH's role can include applications such as fluoride, and can expand into areas like dialysis treatment assistance under nursing supervision.
Step-by-step explanation:
A Registered Dental Hygienist (RDH) working under general or direct supervision is authorized to place medicaments that do not require removal. Under general supervision, an RDH can perform these duties without the dentist being physically present, provided the dentist has authorized the procedures and there is a pre-established diagnosis and treatment plan. In contrast, direct supervision requires the dentist's physical presence during the procedure.
Such placement of medicaments may include application of fluoride or antimicrobial agents that are intended to be left in the oral cavity without the need for subsequent removal. The involvement of RDHs extends beyond basic dental care, as they may also focus on providing dialysis treatments under the supervision of registered nurses, along with reviewing patient history, assessing patient needs, and ensuring accurate and sterile procedures.