Final answer:
The RDA should place a surgical sedative dressing over the wound to protect it, promote healing, and reduce post-operative discomfort.
Step-by-step explanation:
The RDA (registered dental assistant) should place a surgical sedative dressing over the wound immediately following the surgical removal and suturing of an impacted mandibular third molar. The purpose of the surgical sedative dressing is to protect the wound and promote healing by providing a barrier against infection and reducing post-operative discomfort. The dressing also helps to control bleeding and minimize swelling.