Difference between selected and obtained shade for metal-ceramic crown systems.

Purpose: This study evaluated shade differences between selected shades (2 M 2, 3D Master system, Vitazahnfabrik) and obtained shades of crowns made with a gold electroforming metal-ceramic system (Gramm Technik GmbH) veneered with porcelain and compared those crowns with crowns made with In-Ceram alumina blocks (Vitazahnfabrik) in a CEREC 3D machine (Sirona Dental Systems LLC) and with a porcelain-fused-to-metal system (Classic IV gold alloy, Jensen Dental).

Materials And Methods: Ten crown restorations were constructed for each group (gold electroforming, In-Ceram alumina and porcelain-fused-to-metal) following the manufacturers' directions. Shade difference between a selected shade (2 M 2) and the obtained shades was measured using an intraoral spectrophotometer (Easyshade). Data was statistically analyzed.

Results: Shade differences for the three groups were between 1.21-1.56, with the gold electroformed crowns having the lowest mean and the porcelain-fused-to-metal having the highest mean. Statistical analysis with ANOVA revealed a significant difference among the three systems (p < .0001). Further statistical analysis with post hoc Tukey's test revealed a significant difference in means between the porcelain-fused-to-metal group and the other two groups (p < 0.021). No significant difference was detected between the means of the gold electroformed crowns and the In-Ceram alumina crowns (p = 0.981).

Conclusion: Veneered gold electroformed crowns and In-Ceram crowns produced shade matching significantly better than that obtained with porcelain-fused-to-metal crowns.