[Quantitative analysis of sulphur in the liquid of some dental cements]

The ceramometal restoration with porcelain margin have been clinically applied to provide accuracy and esthetics. But, we experienced the cases that the color of the labial marginal area of ceramometal restoration turned dark. Then, the crown was removed and observed. And it was found that the cement color had been changed black. As the result of the ultimate analysis of this cement by means of X ray microanalyzer, some elements; Al, P, S, Ca, Ni and Zn, were detected. As the inclusion of sulphur in commercially available cements was suspected the quantitative analysis of sulphur in the liquid of glass ionomer cement and polycarboxylate cement were done by means of inductively coupled plasma spectrometer. And following results were obtained that sulphur was included 5437 micrograms/ml in the liquid of glass ionomer cement, and 2147 micrograms/ml in the liquid of polycarboxylate cement, respectively. From the above, it is suspected that sulphur reacts on dental metal and causes tooth and gingival discoloration.