Application of noble metal cluster to PMMA resin and influence on mechanical properties and color

To improve the mechanical strength of denture base resin, several types of noble metal cluster were introduced into PMMA, and the mechanical properties and color changes were evaluated. Complex salts of gold, silver, platinum, and palladium were used as the raw materials of noble metal clusters, and after adding each cluster to MMA, polymerization and thermal treatment were performed to produce PMMA-noble metal cluster complexes. Bending deflection, bending strength, and Vickers hardness were measured, and the formation conditions of metal clusters were investigated using EPMA, SEM, and TEM. Furthermore, color changes between before and after metal cluster creation were measured. The bending deflection increased with the addition of silver and platinum, and decreased with the addition of palladium. The bending strength was lowest with the addition of gold, highest with the addition of palladium. Vickers hardness increased with the addition of palladium. Color differences increased with increasing thermal treatment temperature.