- Disclosing a patient's dental records without permission primarily breaches the ethical principle of Confidentiality.
- This principle mandates that patient information must be kept private and only shared with authorized individuals.
- Respecting confidentiality protects the patient's trust and personal privacy.
- Unauthorized disclosure undermines this trust and violates professional standards.
- While autonomy involves patients' rights, and beneficence and justice relate to care and fairness, confidentiality specifically governs privacy of information.

Reference: Principles of Dental Ethics, Volume 1, Chapter 3, Page 45