Shore Hardness of VPS Materials from Unset to Set Consistency

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.