The present invention is a formable dental treatment tray utilizing poly(2-ethyl-2-oxazoline) and a gelatinous active. Blending of the active is accomplished by mixing the Poly(2-ethyl-2-oxazoline) with an active ingredient, such as a peroxide like hydrogen peroxide, carbamide peroxide, sodium perborate, or sodium percarbonate, usually also with water or an appropriate organic solvent. Peroxide concentrations in these new gels can reach a 30% concentration of hydrogen peroxide while maintaining a shelf life of six months at room temperature without developing peroxide decomposition. The gels are applied to an appropriate backing and dried to a gelatinous state. In use, the active is hydrated and regains adhesiveness. Then the tray is pressed and formed around a user's dental arch to form the customizable tray. Multiple active ingredients may be used, with or without peroxide, for accomplishing desired treatment regimens.
