The present invention provides photosensitive compositions and methods of patterning a polymeric image on a substrate, said methods comprising; depositing a layer of photosensitive composition of any one of claims 15 to 22 on the substrate; and irradiating a portion of the layer of photosensitive composition with a light comprising a wavelength in a range of from about 220 to about 440 nm. Each layer includes a first material strand having a first diameter and a second material strand having a second diameter different from the first diameter. Alternatively the structure can be formed by embossing a layer of ink with positive pyramids so as to yield an array of positive embossed pyramids. The mouth piece is dimensioned to reside between the upper and lower teeth of a patient. The roller includes a metal core having an internal bore and a molded plastic bushing lining the internal bore such that the metal core and the plastic bushing include interlocked or bonded structures that essentially prevent the relative rotation between the metal core and the plastic bushing.