Dental composition selected from a root canal sealing composition and a pulp capping composition, comprising:(a) a radioopaque particulate filler；(b) a monomer having at least two groups selected from primary and secondary amino groups and thiol groups； and(c) a compound polymerizable with the monomer (b) in a step-growth polymerization reaction based on at least two groups selected from the following formula (A) and (B) attached to or connected by one or more organic groups:wherein R6, R7 R8, R10 and R11 which are independent from each other, represent a hydrogen atom or a C1-6 alkyl group.
