Shore Hardness of VPS Materials from Unset to Set Consistency
Michael Neglia, Derek Nobrega, Dr. Gerard Kugel, Dr. Ronald Perry
Objectives: To evaluate the transition from the unset to the set stage of seven VPS wash materials. Shore A Hardness was recorded from the unset to the set stage.
Methods: Six marketed VPS wash products were tested: Aquasil UltraLV Fast Set (AQU, DENTSPLY,LOT#100608), EXA'lance Light Body Regular Set (ELB, GC America Inc.,LOT#1012131), Flexitime Light Flow (FLF, Heraeus,LOT#350024), Imprint 3 Quick Step Light Body (IQS, 3M ESPE,LOT#439507), Panasil Initial Contact Light (PCL, Kettenbach,LOT#110251), Take 1 Advantage Light Body Wash (TAL, Kerr,LOT#34149). One experimental VPS light body was tested, Experimental Wash (EXP, 3M ESPE, Lab-FW-Misch-0574). Samples were collected (n=6) and measurements were recorded by Durometer (Zwick) according to ASTM D2240, from the earliest available measurement to a final consistent setting time at 15-second intervals at room temperature (23°C). A one-way ANOVA and a Tukey test were conducted to determine the statistical significance (Minitab version 15).
Results: Final hardness was calculated and used as the baseline for what 100% hardness would be considered and each value was compared according to that value. Each of the individual materials showed a linear behavior between 0 and 80% of the final hardness. This area was used to determine the slope at which setting occurred. EXP was found to have the significantly steepest slope (p<0.05).
Slope Values of Shore A Hardness | |
Materials(n=6) | Mean(SD) |
AQU | 29.4(5.0)c |
ELB | 17.8(1.5)d,e |
EXP | 65.0(8.0)a |
FLF | 24.5(1.2)c,e |
IQS | 38.4(6.4)b |
PQL | 25.1(1.0)c,d |
TAL | 43.9(3.7)b |
Materials with the same letters are not significantly different from each other. |
Conclusions: Of all materials tested, EXP showed the steepest slope during setting indicating that this material may facilitate a shorter setting time of all the materials tested.
Supported in part by 3M ESPE.
Keywords: Dental materials, Effectiveness, Hardness, Impression materials and VPS materials
See more of: Dental Materials 7: Polymer-based Materials-Physical Properties and Performance