A dental jacket made of a hard, solvent free, substantially non-hydrophilic polyurethane elastomer. The jacket elastomer has a hardness of not less than about Shore D65. A polyester or polyether polyol with a functionality greater than two and a molecular weight greater than one hundred is reacted with an isocyanate prepolymer prepared from one or more branched polyester or polyether polyols with a functionality greater than two; and then blending prepolymer and first polyester or polyether polyol with nanoparticles. In one embodiment, the polypropylene glycol triether and the isocyanate prepolymer comprises dicyclohexylmethane 4,4′-diisocyanate.