PURPOSE: To provide an acid-setting dental restoration composition having shortened setting time, improved crushing strength and suppressed cracking tendency caused by drying and shrinking, by compounding two kinds of calcium phosphates having different Ca/P gram-atom ratios.
CONSTITUTION: The titled composition contains (A) is calcium phosphate having a Ca/P gram-atom ratio of 1.30W1.55 (e.g. α- or β-tricalcium phosphate or octacalcium phosphate) and (B) a calcium phosphate having a Ca/P gram-atom ratio of 1.56W2.1 (e.g. hydroxyapatite or tetracalcium phosphate) at a weight ratio (A:B) of 20:1W1:20. The composition is cured by kneading with an acidic aqueous solution of pH3.5W6.5. For example, 1M citric acid solution is adjusted to pH5 with ammonia water and used at a weight ratio (composition/kneading liquid) of 3.1W6. The above composition is preferably added with a fluoride such as calcium fluoride in an amount to attain a Ca/F gram-atom ratio of 4.2W60.
SAOTOME TOSHIYUKI
IINO SHINJI
OSHIMA MINORU
MITSUI TOATSU CHEMICALS