A dental composition comprising a polymerizable acidic compound of the following formula (I): (I) wherein R1 which may be the same or different when more than one R1 is present, represents a hydrogen atom or a methyl group； R2 which may be the same or different when more than one R2 is present, represents a hydrogen atom, a straight-chain or branched C1-6 alkyl group, a C3-8 cycloalkyl group or a straight-chain or branched C2-6 alkenyl group； R3 which may be the same or different when more than one R3 is present, represents a monovalent organic moiety substituted by a group selected from -COOM, -PO3M, -O-PO3M2 and -SO3M, wherein M independently represents a hydrogen atom or a metal atom； or R2 and R3 form together a divalent organic moiety substituted by a group selected from -COOM, -PO3M, -O-PO3M2 and -SO3M, wherein M independently represents a hydrogen atom or a metal atom； L represents a (m+n+1)-valent organic linker group； X represents a hydrogen atom or a group selected from -COOM, -PO3M, -O-PO3M2 or -SO3M, wherein M independently is a hydrogen atom or a metal atom； m is an integer of 0 to 6； n is an integer of 0 to 6； wherein (m+n) is at least 2； provided that when n is 0, then X cannot be a hydrogen atom.
