Objectives: The aim of this study was to evaluate rheological properties of different impression materials using the Shark-fin test. In addition a new method for evaluation of the shark-fin specimens was introduced.
Methods: 10 samples of each impression material (see table results) were made according to the usual shark-fin examination. The specimen was digitised via Optimas 6.2 on a light-optical microscope. The evaluation was carried out with length and area measurement functions of the Optimas 6.2 software . Medians and 25%/75% percentiles were calculated. Statistics: Mann- Whitney- U Test (α= 0.05)
Results:
Material | Manufacturer | Height [cm] median (25%/75%) | Area [cm²] median (25%/75%) |
Permadyne Garant | 3M Espe, G | 1.39 (1.37/1.42) | 26.48 (26.05/27.07) |
Impregum Garant Duo Soft | 3M Espe, G | 1.48 (1.43/1.51) | 29.21 (28.47/29.96) |
Express Ultra Light | 3M Espe, G | 1.49 (1.43/1.54) | 29.24 (28.08/30.64) |
Panasil Contact | Kettenbach, G | 1.35 (1.29/1.40) | 26.49 (25.72/27.90) |
Aquasil Ultra XLV Regular | Dentsply, G | 1.34 (1.30/1.37) | 27.62 (27.62/28.62) |
Conclusion: Comparing height with area the same order of materials was found. Nevertheless the digitised evaluation of specimen should be preferred in comparison to the ruler examination.