A dental composition comprising a polymerizable acidic compound of the following formula: wherein R 1 which may be the same or different when more than one R 1 is present, represents a hydrogen atom or a methyl group; R 2 which may be the same or different when more than one R 2 is present, represents a hydrogen atom, a straight-chain or branched C 1-6 alkyl group, a C 3-8 cycloalkyl group or a straight-chain or branched C 2-6 alkenyl group; X represents a hydrogen atom or a group selected from -COOM, - PO 3 M, -O-PO 3 M 2 or -SO 3 M, wherein M independently is a hydrogen atom or a metal atom; m is an integer of 0 to 6; n is an integer of 1 to 6; wherein (m+n) is at least 2; wherein R 3 is a group of the following formula: wherein R 4 which may be the same or different when more than one R 4 is present, represents a hydrogen atom or a C 1-4 alkyl group; R 5 which may be the same or different when more than one R 5 is present, represents a hydrogen atom or a C 1-4 alkyl group; R 6 which may be the same or different when more than one R 6 is present, represents a hydrogen atom or a C 1-4 alkyl group; R 7 which may be the same or different when more than one R 7 is present, represents a hydrogen atom or a C 1-4 alkyl group; Y represents an oxygen atom or a sulfur atom; Z represents a group -COOM, wherein M independently is a hydrogen atom or a metal atom; a is an integer of 1 to 6; b is an integer of 0 or 1; and c is an integer of 1 to 6; and wherein L represents a (m+n+1)-valent aliphatic or alicyclic linker group. R 1 which may be the same or different when more than one R 1 is present, represents a hydrogen atom or a methyl group; R 2 which may be the same or different when more than one R 2 is present, represents a hydrogen atom, a straight-chain or branched C 1-6 alkyl group, a C 3-8 cycloalkyl group or a straight-chain or branched C 2-6 alkenyl group; X represents a hydrogen atom or a group selected from -COOM, - PO 3 M, -O-PO 3 M 2 or -SO 3 M, wherein M independently is a hydrogen atom or a metal atom; m is an integer of 0 to 6; n is an integer of 1 to 6; wherein (m+n) is at least 2; wherein R 3 is a group of the following formula: wherein R 4 which may be the same or different when more than one R 4 is present, represents a hydrogen atom or a C 1-4 alkyl group; R 5 which may be the same or different when more than one R 5 is present, represents a hydrogen atom or a C 1-4 alkyl group; R 6 which may be the same or different when more than one R 6 is present, represents a hydrogen atom or a C 1-4 alkyl group; R 7 which may be the same or different when more than one R 7 is present, represents a hydrogen atom or a C 1-4 alkyl group; Y represents an oxygen atom or a sulfur atom; Z represents a group -COOM, wherein M independently is a hydrogen atom or a metal atom; a is an integer of 1 to 6; b is an integer of 0 or 1; and c is an integer of 1 to 6; and wherein L represents a (m+n+1)-valent aliphatic or alicyclic linker group. R 4 which may be the same or different when more than one R 4 is present, represents a hydrogen atom or a C 1-4 alkyl group; R 5 which may be the same or different when more than one R 5 is present, represents a hydrogen atom or a C 1-4 alkyl group; R 6 which may be the same or different when more than one R 6 is present, represents a hydrogen atom or a C 1-4 alkyl group; R 7 which may be the same or different when more than one R 7 is present, represents a hydrogen atom or a C 1-4 alkyl group; Y represents an oxygen atom or a sulfur atom; Z represents a group -COOM, wherein M independently is a hydrogen atom or a metal atom; a is an integer of 1 to 6; b is an integer of 0 or 1; and c is an integer of 1 to 6; and