Which of the following is considered an unlawful practice for dental hygienists?

Using unverified techniques is considered an unlawful practice for dental hygienists because it can pose significant risks to patient safety and care quality. Dental hygienists are expected to adhere to evidence-based practices and proven methods to ensure safe and effective treatment. Utilizing techniques that have not been substantiated or validated by current research or accepted clinical guidelines may lead to ineffective or harmful results for patients. Regulatory bodies and professional organizations emphasize the importance of following standard protocols to maintain a high level of care and professionalism within the dental hygiene field.

Providing educational seminars, offering free consultations, and collaborating with other practitioners are all activities that fall within the permissible scope of practice for dental hygienists, as they enhance patient knowledge, provide access to care, and promote teamwork in healthcare settings, respectively.