A dental appliance is described, the dental appliance including a polymeric substrate with a plurality of cavities for receiving one or more teeth, an arrangement of engineered microstructures on the substrate wherein the engineered microstructures include a therapeutic agent. The microstructures may be three-dimensionally engineered on a polymeric film disposed on a major surface of the polymeric substrate, wherein the microstructures extend outwards from the surface. The microstructures also comprise a compound releasable from the three-dimensionally engineered microstructures over a predetermined patient wear time.