What is NOT an allowed duty for a dental assistant?

Conducting dental exams is not an allowed duty for a dental assistant because this task typically falls within the scope of practice for licensed dentists or other dental practitioners. During dental exams, a comprehensive evaluation of a patient's oral health is conducted, which includes diagnosing conditions, developing treatment plans, and making clinical judgments. These responsibilities require a level of expertise and licensure that dental assistants do not possess.

In contrast, the other choices reflect duties that dental assistants are commonly trained and permitted to perform. For instance, performing coronal polishing and taking X-rays are functions that dental assistants can legally complete under supervision, as long as they have received proper training. Similarly, assisting in surgical procedures is also a typical role for dental assistants and involves supporting the dentist during operations, preparing instruments, and managing patient comfort. Thus, the specific responsibilities outlined for dental assistants are designed to support the dental practice while ensuring patient safety and care are prioritized.