Pulp Vitality Assessment — ORE Part 1 MCQ
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Correct answer: B — Laser Doppler flowmetry
Explanation lettering: C = shown as A · A = shown as B · B = shown as C
Laser Doppler flowmetry (LDF) is the most accurate method for assessing true pulp vitality because it directly measures pulpal blood flow (the definition of vitality), rather than nerve sensibility. Meta-analytic evidence shows LDF sensitivity of 81.8–100% and specificity of 100% in differentiating vital from necrotic teeth, substantially higher than sensibility tests: EPT (63.3–91.5% sensitivity, 88–100% specificity), cold testing (0.83 sensitivity, 0.93 specificity), and heat testing (0.86 sensitivity, 0.41 specificity). Pulse oximetry (not listed) has the highest diagnostic odds ratio (628.5) but is not an option. Heat testing (D) shows poor specificity (0.41), producing many false positives. EPT (B) and cold testing (C) are sensibility tests measuring nerve response, not blood flow. Percussion (E) assesses periapical status, not pulp vitality. Despite LDF's practical limitations in everyday clinical use (cost, technical requirements, light scattering artefacts), it remains the reference standard for vitality assessment. The stem's explicit reference to 'blood supply' directs the answer toward true vitality testing.
Reference: Ghouth N, Duggal MS, BaniHani A, Nazzal H. The diagnostic accuracy of laser Doppler flowmetry in assessing pulp blood flow in permanent teeth: A systematic review. Dental Traumatology. 2018;34(5):311–319. https://pubmed.ncbi.nlm.nih.gov/29953720/