A child presents with a history of trauma to primary teeth E and F (maxillary primary lateral incisors) some time ago. The patient now has pain on percussion, a negative pulp test, and color change in those teeth. What is the diagnosis?

Correct answer: C. Pulp necrosis

• A. INCORRECT. Reversible pulpitis presents with pain to cold that lingers briefly, NOT negative pulp test. The pulp is still vital in reversible pulpitis.
• B. INCORRECT. Irreversible pulpitis presents with lingering, spontaneous, or thermal pain but still shows a positive (often exaggerated) pulp test response. A negative pulp test indicates pulpal non-vitality.
• C. CORRECT. Pulp necrosis is the correct diagnosis: (1) History of trauma, (2) Negative pulp test (non-vital pulp), (3) Pain on percussion (periapical inflammation), and (4) Color change (gray/dark discoloration from breakdown of red blood cells and hemoglobin degradation within the necrotic pulp chamber). This classic tetrad following dental trauma is pathognomonic for pulp necrosis.
• D. INCORRECT. An acute apical abscess presents with severe spontaneous pain, swelling, possible sinus tract, and marked tenderness. While pulp necrosis precedes abscess formation, the absence of swelling or sinus tract in this case points to necrosis without active abscess.