Fig. (1) The relationship between immersion medias and different immersion times and thermocycling and total monomer release, abbreviations of groups are: 1: 24 h, 2: 48 h, 3: 72 h, 4: 1 wk, 5: 4 wk, 6: 12 wk. 7: 1000 cycles, 8: 2000 cycles, 9:3000 cycles.