Conclusion

The FDA uses two mechanisms to regulate OTC drugs: drug monographs and NDAs. A drug monograph identifies active ingredients that are deemed to be safe and effective for a specific therapeutic need. Most OTC fluoride-containing dentifrices are regulated through the Anticaries, Antiplaque-Antigingivitis, and Tooth Desensitizer monographs. If a dentifrice contains a drug that is not included in a monograph, it must be approved through an NDA. Therapeutic dentifrices brought to market under one of these two regulatory pathways can make claims related to treating or preventing disease.

The ADA is a professional society that takes great interest in informing the public on the safety and efficacy of oral care products. This is done primarily by awarding its Seal of Acceptance. The ADA Seal of Acceptance program is a rigorous, voluntary process in which manufacturers can choose to participate for specific products.

Fluoride was the first therapeutic ingredient used in dentifrice. Fluoride helps prevent caries by enhancing remineralization and inhibiting demineralization. The three fluoride ingredients approved by the FDA for use in dentifrices are stannous fluoride (SnF₂), sodium fluoride (NaF), and sodium monofluorophosphate (Na₂PO₃F).

Since the introduction of early fluoride dentifrices, many other ingredients have been discovered and added to dentifrice to provide multiple additional benefits, including the following:

• Plaque/gingivitis/malodor reduction: Plaque, gingivitis, and halitosis are caused by bacteria. Antibacterial-containing dentifrices can help prevent these conditions. Stannous fluoride is the only agent currently used in dentifrices sold in the U.S. that is recognized by the ADA as being effective for controlling plaque, gingivitis and malodor.

• Antihypersensitivity: Dentinal hypersensitivity can be treated by chemically depolarizing nerve endings in the tooth or by blocking dentinal tubules. Potassium nitrate is the most common nerve desensitizing agent. Stannous fluoride, arginine + calcium carbonate, strontium acetate, and calcium sodium phosphosilicate are tubule occluding agents used in newer antihypersensitivity dentifrices across the globe.

• Erosive toothwear: While Sodium Fluoride remineralizes and makes fluorapatite more resistant to moderate pH drops, Stannous fluoride deposits a protective layer to prevent loss of mineral in a lower pH acid challenge is the only ingredient recognized by the ADA to significantly prevent erosive toothwear.

• Calculus control: Polyphosphates, such as SHMP, are effective anticalculus agents. They chelate (bind) calcium and inhibit plaque calcification.

• Stain removal/Whitening: Stain removal or tooth whitening is achieved through chemical or physical action. Polyphosphates are good stain removal agents. They displace stain molecules that have attached to the tooth pellicle. Abrasives remove tooth stain through a physical action. Dentifrices with an RDA of 250 or lower are considered safe for everyday use.

Additional dentifrice ingredients include humectants, binders, buffers, flavors, sweeteners, and surfactants. These ingredients stabilize the product and create esthetic benefits for the consumer. They are needed to keep the dentifrice properly mixed with a palatable consistency. Not all dentifrice ingredients are compatible, however, so manufacturers must formulate the chemistry in a way that does not interfere with the bioavailability of the therapeutic ingredients. Creating a dentifrice that delivers important therapeutic and cosmetic benefits, while at the same time being acceptable to the consumer, requires the manufacturer to delicately balance the overall formulation. As noted throughout this course, a dentifrice is a very complex aggregate of chemicals with very specific functions. Not only do these ingredients have to be effective individually, they also have to be compatible with one another. All of these requirements demand very careful formulation and processing in order to be able to manufacture a high quality dentifrice.

This update has shown the market forces have continued to develop new and improved products for the consumer. The therapeutic dentifrices developed have been responsible for a large portion of the caries reduction in the industrialized world. What new oral care therapies await consumers of the future is open for speculation. Most importantly, research has continued to progress, identifying opportunities to deliver enhanced levels of benefit as well as confirmation of new benefits by focusing on key mechanistic aspects of the various active ingredients. We only have to wait to see what new systems may come to bear in this ever-changing marketplace. It will be interesting to see what the future of Oral Care will include!