Tooth whitening compositions and methods

A composition for whitening a tooth surface, comprising chlorine dioxide, oxy-chlorine anions, a thickener component, an aqueous medium, and at least one of a sweetener and a flavorant, wherein the composition comprises at least about 20 ppm chlorine dioxide, no more than about 0.25 milligrams oxy-chlorine anion per gram composition and is substantially non-cytotoxic, and wherein the thickener component is selected from the group consisting of a natural hydrocolloid, a semisynthetic hydrocolloid, a clay, a high molecular weight polyethylene glycol, a high molecular weight polypropylene glycol, a polyethylene oxide, and a carbomer.