Dimensional changes of complete dentures, which were constructed by six conventional polymerization methods, were investigated after polymerization and during storage. The discrepancy at median line and alveolar ridge was larger in the dentures constructed in a water bath at 70°C for 40 min and then at 100°C for 30 min, in a hot press and by microwave polymerization than in a water bath at 70°C for 24 hrs, for 8 hrs and by autopolymerization. The discrepancy at the denture border of the dentures constructed by autopolymerization during storage in water for 30 days was 0.174±0.048 mm and in the case of the dentures constructed by other polymerization methods was less than 0.1 mm. Since the dimensional changes of the dentures during storage in water occurred up to 7 days, it seems reasonable that wearing dentures or occlusional adjustment should be carried out after storage in water for more than 7 days. The discrepancy was 3 to 4 times in the dentures stored in air than in water. When the dentures which were stored in air for 30 days was immersed in water for 30 days, the discrepancy at the denture border of the dentures constructed by autopolymerization was restored to 0.214±0.097 mm, but in the case of other polymerization methods, it was restored to about 0.14 mm.
