Effects of Chemical Activators of Fluorescence on Dental Ceramics
Date Issued
2008
Date
2008
Author(s)
Su, Jian-Bin
Abstract
The natural teeth emit a light blue fluorescence under the exposure to ultraviolet and many commercial dental porcelains added the chemical activators for mimic the fluorescence of the natural teeth. But the literature to the fluorescence of the teeth and dental porcelains were few,lso there is no guide for comparing the fluorescence of restorative materials to natural teeth. People with anterior prostheses may present different fluorescence from their natural teeth when they go to nightclubs or discotheques with ultraviolet illuminations. Neither the different dental porcelain systems nor the different layers or colors of the same system present the same fluorescence. The purposes of this experiment were to identify the chemical activators in commercial dental porcelains, to analyze the relationship between the fluorescence intensity and the proportions of the chemical activators in the dental porcelains, and then adding the chemical activators into commercial dental porcelains and bserving the changes in fluorescence after firing sequence.ine dental porcelains, including: A1 enamel porcelain of the five systems (Procera AllCeram, Cercon Zirconia, IPS Empress II, Noritake Ex-3 and Shofu Vintage) , A1 and B4 body of the AllCeram system, B4 enamel and body of the Shofu system, were used as the samples for the ICP-MS testing. Set up ten groups and each group had 2g of the Empress II A1 enamel powders. Added the CeO2 into second to fourth group with different percentage from 1~3% and added the Eu2O3 into fifth to seventh group with different percentage from 1~3%. Added Eu2O3 1% and CeO2 1% into eighth group, Eu2O3 1.5%and CeO2 0.5% into ninth group, Eu2O3 0.5% and CeO2 1.5% into ten group. Each group made into three sample disks, then the excitation and the emission spectrum of the samples were recorded by using the spectrofluorometer. All the samples were also scanned by spectrophotometer (ShadeEye- NCC) and calculated the ifferences in the color by adding chemical activators.xperimental results: (1)The main inclusions with the five commercial porcelain systems were similar revealed by the resulted of ICP-MS. The chemical activators of the porcelains were all rare earth oxides such as: Ce, Eu, Gd and Y. More than one chemical activator of fluorescence were observed in most commercial dental porcelain systems. (2) The fluorescence intensity did not show a direct relation with the proportions of the chemical activators in the commercial dental porcelains. (3) Adding CeO2 into the Empress II shifted the emission spectrums to 400 nm and decreased the fluorescence intensity and adding Eu2O3 into the Empress II increased the fluorescence intensity. The color changes of the samples after adding the chemical activators were visually acceptable. (4)Adding CeO2 into our synthetic dental porcelain did not show the fluorescence and adding Eu2O3 showed the pink fluorescence.onclusion: Different proportion of chemical activators can be identified in commercial dental porcelains. Adding chemical activator into commercial porcelains may affect the fluorescence intensity without hanging the shade visually. Further investigations are needed.
Subjects
dental porcelain
fluorescence
chemical activators
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