Methods:
4 disk-shaped specimen were produced from 4 A2 shade composite (Pekalite ,Z250, Z350 dentin, Vitalessence) in each thicknesses(0.5, 1, 1.5, 2, 3, 4 mm).color values(L,a,b) were recorded against standard white and black backgrounds with a “color eye 7000” specterophotometer. Under the standard illuminant D65. TP were calculated and compared using ANOVA and tukey test.
Results:
a continuum of values for TP was obtained, ranging from the most opaque (Z350 dentin) to the most translucent (Pekalite) in all of thicknesses. The TP decreased as thicknesses increased. Black background was masked with different minimal thicknesses: 2 mm of Z350 dentin, 3 mm of Z250 or Vitalessence and 4 mm of Pekalite.
Conclusions:
translucency of composites were influenced by thickness and brand. definition of an index for “enough thickness of each composite to mask the oral cavity’s black shadow + A2” provide more information than only “A2” on composite tube and can assist clinician to choose better composite for clinical use.