Which of the following represents a legal barrier for practicing dentistry?

Practicing without an active license is a clear legal barrier to practicing dentistry. Licensing is a fundamental requirement in the dental profession that ensures practitioners have undergone the necessary education, training, and examination to provide safe and effective care to patients. Without an active license, a dental hygienist or dentist does not have the legal authority to operate, which can result in serious legal consequences, including fines, penalties, and potential criminal charges.

This distinction is crucial, as the practice of dentistry is regulated to maintain public safety and uphold professional standards. On the other hand, practicing under supervision, providing services for free, and practicing during emergencies do not inherently constitute illegal barriers. In many cases, professionals may operate under supervision or provide care at no charge as part of community service, and derogatory practices during emergencies may be allowed, especially in dire circumstances where immediate care is necessary to save lives or prevent serious harm.