Table 2.
Polymerization shrinkage at different irradiation times and degrees of conversion
| Irradiation time, s | 10 | 15 | 20 | 30 | 60 | 600 |
| Final conversion, % (SD) | 47.2 (0.3) | 51.5 (0.8) | 53.0 (0.3) | 55.5 (0.8) | 56.1 (0.5) | 59.8 (0.4) |
| Polymerization shrinkage at light-off, % (SD) | 1.2 (1.0) | 2.82 (0.4) | 3.25 (1.0) | 4.1 (0.2) | 5.0 (0.5) | 5.7 (0.7) |
| Final polymerization shrinkage, % (SD) | 2.5a (1.1) | 3.5a,b (0.6) | 4.1b,c (0.8) | 4.7b,c (0.2) | 5.4c (0.5) | 5.7c (0.7) |
| Dark cure, % of final conversion | 15.2 | 10.4 | 9.0 | 8.3 | 6.2 | - |
| Dark cure polymerization shrinkage, % of final shrinkage | 52.8 | 20.3 | 20.1 | 12.6 | 8.3 | - |
Lower case letters indicate statistical differences within a row (Student-Newman-Keuls test, α=0.5).
SD = standard deviation.
Final values taken at 600 s from the onset of photopolymerization at 10 mW/cm2.