A bone cement system (100) is provided having a mixing facility (10) for mixing and dispensing of bone cement, a reservoir container (112) for a monomer, and a conveyor (122). The mixing facility (10) has a mixing cylinder (20), which stores a bone cement powder. The monomer can be conveyed from the reservoir container (112) into the mixing cylinder (20) by the conveyor (122). A sieve element is (4) is arranged between the reservoir container (112) and the mixing facility (10), in order to prevent ingress of the bone cement powder from the mixing cylinder (20) into the conveyor (122). The mixing device (10) included a dispensing opening (23) for dispensing a bone cement mixed from the bone cement powder and the monomer. The dispensing opening (23) includes a shield (1) having at least one through-opening (2). The ratio of the area of the through-opening (2) to the area of the sieve element (4) is at least 1 to 3, and the distance between the shield (1) and the sieve element (4) is at least 1 mm.