A dentist refuses to treat a patient solely because the patient cannot afford to pay. Which ethical principle is most directly violated?

Beneficence is the ethical obligation to act in the patient's best interest and to promote their welfare. Refusing care based solely on inability to pay violates beneficence — the dentist is withholding treatment that would benefit the patient for financial reasons unrelated to clinical care. While dentists are not legally obligated to treat all patients (emergency care is an exception), the ADA Code of Ethics holds that the spirit of beneficence encourages dentists to provide care to patients in need. Justice (fair distribution of resources) is also relevant, but the most direct violation is beneficence — the failure to act in the patient's best interest.