A packaged treatment composition comprising a polymerisable and/or curable composition comprising (1) a packaged first flowable component comprising a source of hydrogen peroxide and (2) a separately packaged second flowable component； the composition comprising a polymerisable monomer or oligomer, a polymer and/or a curing agent, wherein the composition comprises a photoinitiator and wherein the first flowable component is substantially free of photoinitator, the composition capable of forming a solid composition by UV-initiated polymerisation and/or curing following mixing of the first and second flowable components.
