Objective: To evaluate the hydrophilic characteristics of impression materials with various types of surfactants by measuring contact angles (CA) Methods: Six commercial low viscosity (Light Body, LB) impression materials containing various surfactants compared with an experimental one containing a novel PEG-PDMS copolymer surfactant were tested. A goniometer (Rame-Hart) equipped with a digital video camera and DROPimage software was used to obtain and analyze data. The impression materials were mixed and extruded into a mold 3 mm by 10 mm diameter. A razor blade was used to scrape excess material and create a flat surface after slightly overfilling the mold. For measurement after cure, another glass slide was placed on top. The sample was allowed to fully cure according to the manufacturer suggested setting time. A drop of 4µl distilled water was carefully dispensed and placed onto the sample 30 sec after mixing for measurement during cure. Contact angle values were obtained every 0.5 sec for 5 sec from time of placing the water droplet or after 5 minutes for the cured samples. The average of three samples is reported. Results: The following table lists the contact angles in degrees. The results of each measurement were compared by ANOVA and Tukey tests (p≤0.05).
Contact Angle at 0.5 seconds Uncured | Contact Angle at 5.0 seconds Uncured | Contact Angle at 5 minutes, Cured | |
EXP LB (Danville) | 49.4 (3.8) | 41.9 (1.0) | 28.9 (0.1) |
Identium LB (Kettenbach) | 67.1 (1.9) a | 58.8 (2.0) | <5 |
Aquasil Ultra Xtra LB (Dentsply) | 71.5 (2.5) a | 48.4 (2.2) d | 10.0 (0.9) |
Take 1 Advanced (Kerr) | 80.8 (2.1) b | 50.4 (1.7) d | 12.7 (2.5) |
Affinis Precious LB (Coltene) | 81.2 (3.6) b | 38.1 (1.8) | 21.1 (2.2) |
Splash Half Time LB (Denmat) | 96.2 (2.4) c | 67.8 (3.9) | 44.7 (1.9) |
Paradigm LB FS (3M Espe) | 97.8 (2.1) c | 80.9 (3.6) | 48.1 (1.5) |
Means with the same letter are not statistically different at p>0.05
Conclusion : EXP afforded the lowest contact angle for the uncured material. This may suggest that more accurate impressions can be obtained in the presence of moisture. However, Identium and Aquasil Ultra Xtra LB showed the lowest angle for the cured materials.