Method: Impressions of a stainless steel die were made using a conventional (Jeltrate-Plus) and an extended-storage alginate (Hydrogum-5). A polyvinyl-siloxane (HydroXtreme) was used as control. After removal, impressions were stored under the following conditions (n=10): G1 - exposed to air (3h); G2 - sealed in a plastic bag (3h); G3 - sealed in a plastic bag with a 100% relative humidity (3h); G4 - immersed in 2% glutaraldehyde for 10min and then placed in a sealed plastic bag (3h); and G5 - immersed in 2% glutaraldehyde (3h). Dimensional change was measured in digital photographs by comparing the length of the horizontal line at the impression with the same line at the die. The results were statistically analyzed by ANOVA and Tukey’s test (α=0.05).
Result: The results are shown in the Table. Groups G2 to G5 of Hydrogum-5 showed statistically similar results to those of control. For Jeltrate-Plus, only G4 and G5 showed values statistically similar to control. For both alginates, G1 showed the worst results. Polyvinyl-siloxane showed no significant dimensional change when compared to the control group in any storage condition.
Conclusion: The extended-storage alginate showed better results of dimensional stability than the conventional alginate. The polyvinyl siloxane material did not present significant dimensional change under the storage conditions tested.
Means and standard deviations for the measurements of the length of the horizontal line in the impression and in the master die (in mm). Values followed by the same superscript are statistically similar (p>0.05).
|
Hydrogum 5 |
Jeltrate Plus |
HydroXtreme |
Control |
G1 |
24.298±0.150e |
24.393±0.176de |
24.935±0.109ab |
24.894±0.077ab |
G2 |
24.877±0,135ab |
24.603±0.199c |
24.834±0.107ab |
|
G3 |
24.840±0.116ab |
24.583±0.138cd |
24.903±0.154ab |
|
G4 |
24.825±0.153ab |
24.776±0.101bc |
24.994±0.061a |
|
G5 |
24,953±0,154ab |
24,832±0,126ab |
24,919±0,128ab |