Comparative Translucency of Proprietary Composites in Relation to Tooth Structure

Objective: The purpose of this study was to evaluate the translucency of current opaque, dentin, body and enamel-shade composites from different manufacturers. This will provide information to dentists on comparative translucencies of proprietary composites.

Methods: Specimens were made using a split ring mould (13mm in diameter and 2mm in thickness) using 34 different resin composites (n=5/group). The samples were then light cured. Enamel and dentin, obtained from extracted human teeth, were prepared by longitudinally sectioning these teeth using a micro-slicing machine. L*a*b* color values were recorded against both white and black standard backgrounds with a Minolta Chroma Meter CR-300 under the CIE illuminant D65 (which corresponds to ‘average' daylight). Translucency parameter values were calculated and statistically analyzed using ANOVA and Tukey's test (P<.05).

Results: A continuum of translucency values resulted, ranging from the most opaque (Filtek Plus A2D) to the most translucent (Ceram X Duo E2). Three broad categories of composite translucency could be identified, however highest and lowest values between these categories were not distinctly different. Opaque and dentin shades together provided a similar range of low translucency. Regular and body shades showed a range of intermediate translucency and all enamel shades occupied a range of higher translucency. Translucency parameters calculated from extracted teeth showed an expected wide variation. Average values obtained for multiple enamel samples showed some correlation with enamel shade composites. Average dentin translucency was between the low-translucency and intermediate-translucency composites. .

Conclusions: The different types (enamel, body, dentin and opaque) of composite shades from different manufacturers provide a wide range of available translucencies. Three broad categories can be identified. The translucency parameters of proprietary composites within each category can be taken into account to assist in the achievement of optimal esthetics when attempting to block out discoloured tooth structure or replicate normal tooth translucency.