[Study on the setting reaction of the zinc phosphate dental cement (1). Effects of aluminum in liquid on setting reaction (author's transl)].

The liquid of zinc phosphate dental cement contains Al3+ and Zn2+, and these ions effect greatly on the setting reaction of the cement. When zinc oxide powder is mixed with this cement liquid, reaction products in the set cement are amorphous and not made sure by X-ray diffraction. Therefore the setting reaction of zinc phosphate cement is not certain. In this paper the effects of Al3+ on the setting reaction of cement are examined by X-ray diffraction, thermal analysis and infrared spectrum, and set cements are observed by SEM and microradiography. Judging from these results, it is conclude that Al3+ in the cement liquid precipitates amorphous aluminium phosphate due to change of pH of liquid when it is mixed with zinc oxide powder.