Pot life is long and the present invention, X-rays and to prevent leakage or fall off by making close contact with and bonded to the tooth root canal filling material or prosthesis easily removed, a simple fluidity operation excellent sealability and contrast property, readily removable dental curable composition that can be easily removed as needed further, and to provide a filling kit. And a polymerizable monomer mixture containing a polymerizable monomer having an acidic group (A) molecule, A dental composition containing a polymerization initiator (B), The component (A) of, containing or long chain polymerizable monomer having the structure of 17 or more atoms (A ) chain lengths, And a [a] the parts by weight of the component when it is assumed that 100 parts by weight of component (A) (A), and further containing (D1) soft resin material in the composition and / or further (A When the (a), (b), and (d1), respectively (A), (B), the parts by weight of the component (D1) in the case that 100 parts by weight total of) component (B) component, satisfies dental curable composition formula (1) to (5). 70 ≦ (a) ≦ 99.99 ······· (1) 0.01 ≦ (b) ≦ 30 ········ (2) 1 ≦ [a ] / 5+ (d1) / 1 ···· (3) [A ] ≦ 95 ············ (4) And (d1) ≦ 250 ··········· (5)本発明は、除去しやすい暫間補綴物や根管充填材料を歯質に接着および密着させることにより脱落や漏洩を防止し、操作が簡単な流動性を示し且つ可使時間が長く、X線造影性と封鎖性に優れ、さらに必要に応じた除去も容易にできる易除去性歯科用硬化性組成物および充填用キットを提供する。(A)分子内に酸性基を有する重合性単量体を含有する重合性単量体混合物および、(B)重合開始剤を含有する歯科用組成物であって、前記(A)成分中に、(A’)鎖長17原子数以上の構造を持つ長鎖重合性単量体を含むか、および/または前記組成物中に(D1)軟質樹脂材をさらに含有し、そして(A)成分を100重量部とした場合の(A’)成分の重量部を[a’]とし、さらに(A)成分と(B)成分の合計を100重量部とした場合の(A)、(B)、(D1)成分の重量部をそれぞれ(a)、(b)、(d1)とした際に、下記式(1)~(5)を満足する歯科用硬化性組成物。70≦(a)≦99.99・・・・・・・(1)0.01≦(b)≦30・・・・・・・・(2)1≦[a’]/5+(d1)/1・・・・(3)[a’]≦95・・・・・・・・・・・・(4)および(d1)≦250・・・・・・・・・・・(5)
