Translucency of “Cloud-Shade” and “One-Shade” Resin Composites, Color Difference Metrics

Objectives: To compare the translucency parameter (TP) of two “cloud shade” and three “one-shade” resin composites
Methods: The “cloud-shade” composites were 3M experimental composites – 3 Shades (3ML - light, 3MM - medium, 3MD - dark), and SimpliShade – 3 Shades (SSL - light, SSM - medium, SSD - dark), while the “one shade” composites were Omnichroma (OCH), Admira Fusion x-tra (AFX), and Venus Diamond One (VDO), with n=5 per shade. Polymerized composite samples (10 mm in diameter, 2-mm thick) were polished using PoGo disks for 40 seconds. TP measurements were performed using a benchtop spectrophotometer, against white and black background. CIEDE2000 and CIELAB TP values (TP₀₀ and TP_ab, respectively), were calculated. The data was analyzed by analysis of variance at a=0.05 level of significance.
Results: TP₀₀ and TP_ab values were significantly different (p<0.001) yet strongly correlated (r=0.99), with the conversion equations as follows: TP₀₀ = 0.845 × TP_ab + 0.016; TP_ab = 1.159 × TP₀₀ + 0.116.
Conclusions: The “one-shade” composites exhibited higher TP values than the “cloud-shade” composites, which might explain the need to use “blockers” in certain types of restorations. TP₀₀ and TP_ab values were analogous and strongly correlated yet significantly different.