Methods: Four composite materials were tested: Group 1, AuraTM (SDI, Australia); Group 2, LunaTM (SDI); Group 3, LlisTM (FGM, Brazil); Group 4, OpallisTM (FGM); Samples (n=6 for each group) were prepared in stainless steel tubular molds (8mm x 4mm internal diameter) according to the Depth of Cure protocol specified in ISO 4049. Half of the samples were cured for 10 seconds with a Radii Plus (SDI) curing light and the other half were cured for 20 seconds. Uncured composite was removed from the bottom of the sample and the remaining composite height was measured with a caliper. Sample heights were then divided by 2 according to ISO 4049. Mean depth of cure and standard deviation were calculated for each sample. To measure radiopacity, one (1) 1mm x 15mm diameter disc was prepared for each composite material and radiographs were taken using a 2200 digital radiograph machine set at 70kV, 4mA, 0.09s exposure time connected to a RVG6100TMdigital imaging sensor. Radiopacity levels were determined from a 0.5mm stepped aluminum wedge. One-way ANOVA and Tukey tests were conducted on depths of cure for each composite for both cure time (p<0.05, CI= 95%).
Results:
|
Avg. Depth of Cure (mm) |
|
Composite |
10 sec |
20 sec |
Group 1 |
2.38A |
2.76A |
Group 2 |
2.76B |
3.16B |
Group 3 |
1.67C |
2.06C |
Group 4 |
2.29A |
2.94A,B |
1Materials with the same letter are not significantly different from each other.
Composite |
Radiopacity (mm Al) |
Group 1 |
3.00 |
Group 2 |
1.84 |
Group 3 |
2.73 |
Group 4 |
3.12 |
Conclusion: While no relationship exists between radiopacity and depth of cure, the composites did vary significantly in depth of cure. For both the 10 and 20 second cure times, Group 3 was the shallowest depth of cure and Group 2 was the deepest. Group 1 and Group 4 had similar cure depths.