抄録
The solubility of luting cements was investigated in an environment of flowing buffered solutions of organic acids, and experimental results were used to standardize the condition of buffered solutions of organic acids. Then the influence of the differences of zinc phosphate cement film thickness, liquid-powder ratio, and cement film thickness in the marginal area of full cast crown, etc., on the solubility of zinc phosphate cement were investigated.
The experimental results obtained were as follows:
1. The effects of citric acid on the solubility of cements were particularly remarkable. The cements tended to be most soluble in solutions with high molarity and with low pH. The solubility of glass ionomer cement was much less than those of zinc phosphate cement and polycarboxylate cement.
2. The difference of zinc phosphate cement film thickness slightly affected the depth of dissolution of cement. Of course, the thicker the cement film at the site of dissolution, the greater the space resulting from dissolution. Even with an increase of liquid-powder ratio, the solubility showed a slight decrease. The depth of dissolution of cement film decreased with the decrease of zinc phosphate cement film thickness in the marginal area.
3. Only in the area of the burnished margin of the crown and in the area of the suppcsed subgingival margin of the crown covered with artificial gum was there no dissolution of zinc phosphate cement film.
