Residual Monomer Toxicity — MFDS Part 1 MCQ

Instant feedback + full explanation. One question, done properly.

ModerateDental MaterialsResidual Monomer ToxicityMFDS Part 1

A patient reports burning of the denture-bearing mucosa shortly after insertion of a newly processed polymethyl methacrylate denture. The fit is satisfactory, and there is no clinical evidence of Candida-associated denture stomatitis. Which effect of residual methyl methacrylate monomer best explains this presentation?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: D — Irritation and sensitisation of the denture-bearing mucosa

Explanation lettering: E = shown as A · C = shown as B · B = shown as C · A = shown as D · D = shown as E

The correct answer is A. Residual methyl methacrylate can elute from incompletely polymerised PMMA denture bases. Contact with the denture-bearing tissues may cause chemical irritation and cytotoxic effects, producing burning or erythema; it may also provoke hypersensitivity or allergic reactions in susceptible patients. The close temporal relationship to denture insertion, satisfactory fit and absence of evidence for Candida-associated inflammation support this material-related explanation. Options B–D describe potentially desirable physical properties, but residual monomer does not provide these benefits and instead indicates incomplete conversion. Residual monomer is also not an antifungal treatment and does not reliably prevent Candida adhesion, excluding E.

Reference: Keul C, Seidl J, Güth JF, Liebermann A. Impact of fabrication procedures on residual monomer elution of conventional polymethyl methacrylate (PMMA)—a measurement approach by UV/Vis spectrophotometry. Clinical Oral Investigations. 2020;24:4519–4530. Clinical relevance section. https://pubmed.ncbi.nlm.nih.gov/32424461/