Which of the following is a permitted function for a Dental Hygienist?

The role of a dental hygienist is well defined within the scope of practice, which delineates permitted functions. Taking impressions for final fixed or removable restorations is generally a task that falls within the expanded duties of a dental hygienist, provided they have received the appropriate training and certification. This function is essential for creating accurate models and ensuring proper fitting of dentures or other restorations.

The other options present some tasks that may either not fall within the hygienist's scope or are subject to supervision or specific conditions. For example, cementing temporary restorations may not be permitted without a supervising dentist's oversight, as it often requires diagnosis and treatment planning. Similarly, applying dentin desensitizing solutions may require specific guidelines depending on the state regulations governing the practice. Lastly, coronal polishing typically requires supervision to ensure proper technique and safety for the patient, reaffirming the collaborative nature of dental practice involving various roles and responsibilities.

Therefore, taking impressions for restorations, when performed within the legal framework and with proper qualifications, is recognized as a permitted function for dental hygienists.