A dental composition comprising a polymerizable acidic compound of the following formula (I):whereinR1 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； orR2 and R3form 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.
