The thermal and mechanical properties of dental base materials cured by microwave and conventional heat methods were studied. The commercial dental base poly(methvl metacrylate) (PMMA) powder and liquid were mixed in a 3/1 ratio. They were polymerized by a peroxy catalyst at 63degreesC, then cured with a boiling water temperature and microwave radiation for periods of 5, 10, 15, 20, 25, 30, and 35 min for heat curing and 1, 2, 3, 5, and 7 min for microwave radiation. The microwave radiation outputs used were 500 and 700 W. The products of 5-min heat curing and 1-, 2-, and 7-min microwave curing were soluble in chloroform. All the others were partially soluble. The viscosity-average molecular weights of the soluble samples were about 1 x 10(6). The thermal properties of the polymer samples were studied by differential scanning calorimetry