A polymerisable dental filling and sealing composition is provided which comprises a mixture of at least one resin containing on average at least two acrylate or methacrylate groups and a copolymerisable methacrylate or acrylate monomer, which has a low viscosity compared with said resin, the copolymerisable monomer being present in an amount such that the composition can be introduced by syringing into a cavity having a diameter of less than 1 mm.