Which pulp test is LEAST reliable on primary and newly erupted permanent teeth?

Correct answer: B. Electric pulp testing

• A. Percussion is simple, well tolerated and the most reliable clinical test in children — it assesses periodontal ligament inflammation directly.
• B. CORRECT. The ELECTRIC PULP TEST is notoriously unreliable in children. Immature teeth have incompletely developed plexus of Raschkow innervation, so a vital tooth may not respond and give a FALSE NEGATIVE. Equally, young patients frequently report a sensation from anxiety or from current conducted to the gingiva, giving a FALSE POSITIVE. It is also avoided after trauma, where transient nerve paresis makes readings meaningless for weeks or months.
• C. Palpation reliably detects periapical or furcal swelling and tenderness in children.
• D. Radiographs remain essential and reliable, particularly for detecting the FURCATION radiolucency typical of primary molar pathology.

Note: In primary molars, pathology appears in the FURCATION rather than at the apices, because of the abundant accessory canals in the pulpal floor.