Location of the allergenic monomer in warm-polymerized acrylic dentures. Part II: Experiments aimed at establishing guidelines for production of acrylic dentures suited for patients allergic to acrylic monomer and complementary investigations.

An account has been given of a patient with denture sore mouth caused by allergy to the denture material (Part I). In the continued investigation the residual monomer or part thereof was found to be the allergen. Patch testing of the skin with drillings from the upper and lower dentures made of a "warm-polymerized" methyl methacrylate resin was carried out with special reference to the topography of the distribution of the allergenic factor within the dentures. Only that surface of the upper denture that is in contact with the hard palate and the maxillary crista were allergenic. All other surfaces of the upper denture as well as the complete lower denture were non-allergenic. The resin was, in other words, inhomogeneous as regards the allergenic factor. An analysis of the test castings showed that the allergenic properties in the resin are located in the surface and that the resin was free from allergens below the "allergenic film" (Parts I and II). A non-allergenic, extraordinarily well-fitting denture was produced from the same make of acrylic as that used for the non-tolerated denture. It was made by a new technique, "directed polymerization," comprising initial application of heat centrally in the cuvette (a metal cup surrounding the gypsum), including tin-foiling of the palatal half of the mould. The production of the denture was based on experience from tests with test castings. A check-up 18 months later showed no stomatitis and the retention and stability of the denture were very satisfactory, and tests with the original model of the upper gum showed that it had an excellent fit.