[Effect of different mixing and curing methods on the mechanical properties of denture base resin]

To investigate the differences between the mechanical properties of denture base processed by traditional mixing and malaxation method, and by traditional hot water polymerization and electrical heat-polymerization.

Samples used in this investigation were commercial acrylic denture base resin made by using two different mixing methods, and by using two different curing methods. The samples were assigned to 4 test groups. Group 1: traditional mixing + hot water polymerization. Group 2: malaxation + hot water polymerization. Group 3: traditional mixing + electrical heat-polymerization. Group 4: malaxation + electrical heat-polymerization. Surface hardness, flexural strength, flexural modulus, and impact strength were tested of each sample.

The mean of the four groups' surface hardness was 19.4, 21.2, 22.3, 23.2 N/mm2, and of flexural strength was 58.58, 63.32, 66.73, 63.76 MPa, and of impact strength was 1.42, 1.53, 1.77, 1.78 KJ/m2, and of flexural modulus was 2311.38, 2417.82, 2566.36, 2400.37 MPa.

Surface hardness and impact strength of malaxation method + electrical heat-polymerization group are higher than those of traditional mixing + hot water polymerization group.