Something worth smiling about

Whitening composition enables oral bleaching agents to do a more effective job

The U.S. Patent and Trademark Office has issued patent No. 8,137,658 to William Prosise, senior manager, Oral Care research and development and Global Technical Services. . Prosise What is it? Named “Tooth Whitening Compositions,” the patented product is a liquid, substantially anhydrous tooth whitener that places an effective bioadhesive tooth whitening ingredient onto teeth. Because the composition adheres to teeth, it allows the bleaching agent more time to penetrate the tooth enamel. This provides more effective teeth bleaching, even with relatively low levels of bleaching agent. Applications Over the past 15 years, the tooth whitening industry has developed from treatments in dental offices to self-application with over-the-counter whitening products consisting of tooth whitening trays, whitening strips, paint-on whiteners and toothpastes with whitening ingredients. In order to be a successful whitening product, the composition of the whitener must provide sufficient activity of the active ingredient, an enhanced degree of retention on the teeth, an ability to penetrate the tooth enamel and an effective way to bleach stained teeth.

Tea-stained hydroxapatite disks (artificial teeth), bleached with paint-on whitening agents. Top disk is stained only; bottom is unstained. Others are stained and bleached with variations on patented formulas.

Although successful, the whitening process of trays and gels, as well as strips, can cause soft tissue irritation when the whitening composition comes into contact with the gingival area. In order to prevent this, it’s important to limit the concentration of whitening agent while also limiting its contact with gums and soft tissue.

Benefits
Prosise’s patent uses the active ingredient hydrogen peroxide (H₂O₂) as a complex with polyvinylpyrrolidone to create bioadhesion or retention on the teeth, allowing a deep penetration of tooth enamel, a longer delivery of the composition onto the teeth, and superior bleaching of stained teeth.

When tested, results showed that after five minutes, the whitening formulations were well-retained on the tooth surface. Additional tests confirmed good penetration into the teeth, high bleaching activity, and thus, excellent whitening effects.

A line of tooth whitening ingredients known as Peroxydone™ complexes is commercially available from Ashland. Additionally, these ingredients are currently used in several commercially available tooth whiteners made by Prosise’s patented technology.

Prosise was also granted a U.S. patent for using Peroxydone complexes in making dissolvable whitening strips for teeth. The technology is currently being used in several commercially available dissolvable whitening strips.