Final answer:
The services dental hygienists can provide are detailed in the dental practice act specific to each state, which outlines their scope of practice and regulations.
Step-by-step explanation:
Laws that explain what services dental hygienists can provide can typically be found in each state's dental practice act. Dental practice acts are pieces of legislation that define the scope of practice, educational requirements, licensure, and regulatory oversight for dental professionals. As laws differ from state to state, the actual services that dental hygienists are authorized to provide can vary significantly. However, these acts generally outline procedures such as dental cleanings, preventive care, patient education, and, in some states, administering local anesthesia or performing certain restorative procedures under the supervision of a dentist.