Curing Depth of a Colored Polyacid Modified Composite Resin

Methods: The DoC of the PAM-C Twinky Star® (Voco, all shades), the PAM-C Glasiosite® (Voco, shade A2 and A4) and the fine-hybrid composite resin Z100® (3M ESPE, shade A2 and A4) was determined by using a digital penetrometer test method (J Dent 1993;21,305). The materials were cured in bulk using a conventional halogen-based unit (Elipar trilight, 450mW/cm², 40sec. [E=18J/cm²] and 800mW/cm², 40sec. [E=32J/cm²]) and a LED curing unit (Elipar Freelight 2, 1000mW/cm², 20sec.[E=20J/cm²]) in split stainless steel moulds (10mm long, 4mm in diameter). Immediately after curing, the height (mm) of the cured material was measured and taken as the DoC. Statistically significant differences among mean values were detected with a two-way ANOVA and ranking of the means was performed using the Student-Newman-Keuls multiple comparison test at the 95% confidence level.

Results: Mean DoC (n=5) for all materials and shades varied as follows: 4.705-8.870mm, 3.672-8.050mm and 4.090-7.357mm, respectively for E=32, 20 and 18 J/cm². 2-way ANOVA revealed that the DoC depended significantly (P<0.001) on the shade of the material and the curing device. Moreover there was a significant interaction (P<0.001) between these factors indicating that the energy densities affected the different shades differently.

Conclusions: From this study it became clear that the DoC differs significantly among the different materials and the different shades. The Twinky Star shade blue shows the highest DoC compared to the Glasiosite and Z100 shades A2 and A4. The curing device with the highest energy density results in the highest curing depths.