PROBLEM TO BE SOLVED: To provide a two-paste type root canal-filling sealer composition having good wettability to tooth material； less unpleasant odor, irritation, and harmful effects； an excellent biocompatibility； a sufficient allowable operation time suitable for root canal-filling； small dimensional change after curing； and an ability of allowing a cured material to be easily removed during the retreatment of root canal, the composition being easy to be collected and kneaded, being free of differences in various characteristics due to differences in engineers, and being stable in its characteristics.SOLUTION: According to the present invention, a root canal-filling sealer composition consists of: (a) a polymer of an acid group-containing polymerizable monomer in which part or all of the acidic group forms a salt with an alkali metal； a first paste containing (b) a non-acid reactive powder and (c) water and having a pH in the range of 3.5 to 5.5； and a second paste containing (d) an acid-reactive inorganic powder, (c) water, and (e) a thickener. A cured product obtained by kneading consists of (a) 3 to 20% by weight of the polymer of the acid group-containing polymerizable monomer； (c) 15 to 60% by weight of water； and (d) 30 to 70% by weight of the acid-reactive inorganic powder.SELECTED DRAWING: None【課題】歯質に対する濡れ性が良く、不快臭や刺激、為害作用が少なく生体親和性に優れ、根管充填に適した操作余裕時間を有し、硬化後の寸法変化が少なく、更に再根管治療時に硬化物を容易に除去可能であり、簡便に採取や練和が可能で術者の違いで諸特性に差が生じず、安定した諸特性を得られる２ペースト型根管充填用シーラー組成物の提供。【解決手段】（ａ）酸性基の一部又は全部がアルカリ金属と塩を形成する酸性基含有重合性単量体の重合体、（ｂ）非酸反応性粉末及び（ｃ）水を含み、ｐＨが３．５～５．５の範囲の第一ペーストと、（ｄ）酸反応性無機粉末、（ｃ）水及び（ｅ）増粘剤を含む第二ペーストとから、なる２ペースト型根管充填用シーラー組成物。練和して得られた硬化物が（ａ）酸性基含有重合性単量体の重合体：３～２０重量％、（ｃ）水：１５～６０重量％、（ｄ）酸反応性無機粉末：３０～７０重量％の２ペースト型根管充填用シーラー組成物。【選択図】なし
