Spectrophotometric comparison of the colorimetric data of three dark color abutments overlaid by four types of all-ceramic crowns

CHEN Yi-fan; LI Xiao-min; ZHANG Lin; WANG Jian

doi:10.15956/j.cnki.chin.j.conserv.dent.2015.07.006

Abstract：AIM:To evaluate the colorimetric parameter of 3 dark color abutments overlaid by 4 all-ceramic crowns using a digital dental spectrophotometer. METHODS: Abutments of Co-Cr alloys, Au-Pt alloys and ND8 (n=10) were made and were respectively tried in 4 groups of all-ceramic crowns (Procera aluminia, Procera zirconi-a, Lava zirconia and IPS E. max glass-ceramic lithium disilicate-reinforced monolithic crown) (n=10) respectively. The colorimetric data of the cervical, body and incisal sites of the samples were recorded and analyzed by a spectropho-tometer. The CIE L?a?b? values were measured again after veneer. The unglazed A2 ( Vitapan Classical) shade tab was used as the control. The L?a?b?values and the color difference between the samples and control were calculated and statistically analyzed. RESULTS: There was significant difference of the lightness and saturation among 3 abut-ments. But after all-ceramic copings were tried in, the difference of the L?values of the Pro-Alu copings and E. max HO copings decreased greatly. TheΔE value of the Pro-Alu copings was the smallest among all ceramic copings. And the ΔE value of the copings on the ND8 abutment was smallest among 3 abutments. After veneer, the consistency of the L? a?b? values of all the copings increased, the IPS E. max HO crowns had very close L? values and the Pro-Zir <br> crowns had similar a?b? values in 3 groups of abutments. CONCLUSION:4 ceramic copings can promote the light-ness and hue of the dark abutments. All the copings on the ND8 abutment had small ΔE values. Veneering porcelain can increase the colorimetric match between the abutments to some extent. IPS E. max HO crowns have little difference of lightness and Procera zirconia has little difference of saturation among the abutmens.