The optical property of four different all-ceramic crowns on the light color core ND1 substructure / 实用口腔医学杂志

ABSTRACT

Objective:To evaluate the optical property of the light color core substructure ND1 overlaid by 4 different all-ceramic crowns respectively and to study the color difference between the crowns and target tab.Methods:Light color(ND1)substructures were made and were respectively tried in 4 groups of all-ceramic crowns (Procera alumina,Procera zirconia,Lava zirconia and IPS E.max glass-ceramic lithium disilicate-reinforced monolithic,n =10).The CIE L*,a*,b* values of the cervical part,body and incisal site of the samples were recorded and analyzed by a spectrophotometer before and after veneer.The color difference between the all-ceramic crowns and target A2 dentin tab was evaluated.The spectral integral transmittance of the 4 copings was measured by a spectrophotometer.Results:The L* values of the abutments was increased by all-ceramic copings of the 4 groups,a*values were decreased but b* changed inconsistently.After veneer,the L* values of all the copings declined significantly,the values of a* and b* increased.When compared with A2 tab,the ΔE of the crowns was 1.27 ~4.17.The mean value range of the transmittance of the coping wasE.max-LT A2 >Pro-Alu >Lava-Zir >Pro-Zir.Conclusion:The lightness,hue and light transmittance of the 4 ceramic copings are different.After veneer with A2 dentine,the difference of the lightness is declined but the difference of the hue is signifi-cant.The color difference of the Lava-Zir and IPS E.max is clinically unacceptable.