A dental hygienist may NOT make initial access preparations when performing which task?

A dental hygienist is not permitted to make initial access preparations during the task of changing bleach pellets because this task typically involves the potential for accessing deeper structures within the tooth, which falls under the category of irreversible procedures. Initial access preparations are specifically about preparing a cavity for restorative work, which should only be done by a dentist or under their direct supervision.

In contrast, tasks like placing cotton rolls, removing temporary restorations, and irrigating the patient’s mouth are generally within the scope of practice for a dental hygienist. These activities do not involve modifying the tooth structure in a way that requires the specific training and licensing of a dentist. Thus, changing bleach pellets, which could imply a preparation for subsequent restorative work, is outside the hygienist's regulatory allowances, highlighting the importance of letting dentists perform more invasive procedures that require access preparation.