Polysulfide Disadvantages — NDEB AFK MCQ
Instant feedback + full explanation. One question, done properly.
Educational content. Not a substitute for clinical judgement or local policy.
Reveal the answer and explanation
Correct answer: B — Unpleasant odour, staining, and poor dimensional stability over time
Polysulfide (mercaptan/Thiokol) impression materials have several disadvantages compared to PVS: unpleasant sulfur odour, potential to stain clothing, messy handling (lead dioxide catalyst), longer setting time, and ongoing polymerisation causing dimensional instability over time (must be poured promptly). They also have lower elastic recovery. Their main advantages are low cost and excellent tear resistance. PVS has largely replaced polysulfide in modern practice.
Reference: Anusavice – Phillips' Science of Dental Materials, 13th ed., 2022