| 摘要 |
A dental filling and prosthetic compns. was manufd. by pptg. a Ca phosphate from aq. medium at pH 10-12 to give a gel with Ca-P mole ration between those for hydroxylapatite and whitlockite. Thus, a soln. of 16.75g (NH4)2HPO4 in H2O and 150ml concd. NH3 was added over 20 min to 130ml 1.63 N Ca(NO3)2 and 125ml concd. NH3, boiled 10 min, cooled and filtered. The ppt. was heated to 1230≦̸C over 115 min and cooled to give a strong white ceramic material.
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