The New Toothpastes

By Irwin D. Mandel, DDS

Fluoride toothpastes that fight cavities have become common. The current competition among products is for the additional benefits they can offer -- with anti-tartar and whitening leading the way. Toothpastes serving special populations have been increasing and now include desensitizing dentifrices, natural toothpastes, smokers toothpastes, and one designed for people with xerostomia. The newest toothpastes are multibenefit products that include among their properties a clinically demonstrated anti-gingivitis effect -- such as Crest Gum Care and Colgate Total, which was recently cleared by the Food and Drug Administration for antiplaque/antigingivitis as well as anticaries effects.

Article copyright 1998 Journal of the California Dental Association.
Photographs copyright of the authors.

Historical Background

White teeth have been popular attributes of beauty in many societies since ancient times. In the Bible, when Jacob blessed his children, he promised Judah teeth whiter than milk. According to Cicero, white teeth are the first requirement of beauty. Literature is replete with allusions to teeth comparable to shining pearls. When nature did not live up to expectations, help was elicited from chew sticks and fiber sticks as natural toothbrushes and from a wide range of dentifrice ingredients including ground animal bones (often burned to produce charcoal), egg shells, pumice or chalk as abrasives admixed with honey, salt, myrrh, cinnamon and/or oils.1

In colonial America, dentists mixed their own powders and pastes, often advertising them in local newspapers. Their "special" properties made the mixes practice builders and profit centers.2 Dental powders and creams became increasingly popular when the toothbrush was re-invented by William Addis about 1770 in England and spread to the United States after the Revolutionary War. The toothbrush was originally invented in China hundreds of years before, but technology diffusion was slow and re-invention frequent. Dentifrices were originally sold in ceramic jars into which all family members dipped their damp toothbrushes. The more fastidious people, who undoubtedly were equally appalled by familial toothbrushes, were not accommodated until 1892 when Dr. Washington Wentworth Sheffield, a dentist in New London, Conn., invented the toothpaste tube. The collapsible metal tube allowed individual portions for each member of a family.3

During the 19th century, imported English dentifrices were superseded by vigorously marketed American brands. Psychological advertising evoked fear and embarrassment and lauded the simple solutions provided by products that saved teeth and left them "as white as driven snow and filled the breath with odors of springtide."2 Not mentioned in these exaggerated claims was the fact that some products were harmful to teeth, containing acids as tooth whiteners and highly abrasive agents as polishers. Beginning in 1909, Professor William J. Gies at Columbia University began an extensive research program relating the composition of various products to their advertising claims. During a 10-year period, he exposed the fake claims and their dangers. Support for American Dental Association action grew, and in 1928 the ADA's Bureau of Chemistry, modeled after the American Medical Association's program, was established. In 1930, the Council on Dental Therapeutics came into being and soon launched a formal acceptance program for dental drug products. The first fluoride dentifrice was accepted in 1960.2

The Current Scene

Dentifrices accepted by the ADA Seal Program are in three general categories -- desensitizing, fluoride and fluoride with tartar control. A variety of other products, such as various whitening products, are being sold but have not applied for nor been granted the ADA Seal. The procedure for seeking approval of whitening products is described in a supplement to the Journal of The American Dental Association, April 1, 1997. Most dentifrices have similar basic ingredients:

-  Abrasives (20 percent to 50 percent);
-  Humectants to prevent water loss (20 percent to 40 percent);
-  Water (20 percent to 35 percent);
-  Binders to stabilize and prevent separation (1 percent to 2 percent);
-  Detergents (1 percent to 3 percent); and
-  Flavors, sweeteners and preservatives (1 percent to 3 percent).4

The therapeutic components are the various fluorides; antitartar compounds; and desensitizing, antibacterial and whitening agents. Dentifrices are available as pastes, gels and liquids in tubes or pumps.

Since the mid 1950s, much of the competition among toothpastes has involved which kind of fluoride is most effective. Fluoride was the first of the therapeutic additions to the basic dentifrice formulations. Stannous fluoride, sodium monofluorophosphate, sodium fluoride and amine fluoride (sold outside the United States) all have their partisans, but the clinical efficacies of properly formulated products are comparable. Advertising and taste rather than therapeutic superiority determine the market advantage. During the past decade, however, it has not been enough for a dentifrice to prevent tooth decay or create a smile that will win the man, woman or job of one's dreams. Now, it seems, a dentifrice must fight tartar, plaque and gum disease as well. And manufacturers do not want to forget "niche" consumers -- smokers, natural product fans, people with tooth sensitivity, and those with dry mouths. Increasingly intrusive has been a growing demand not just for stain removal and tooth brightening but for actual whitening of the inherent tooth color.

Anti-Tartar Products

One of the first products to venture beyond fluoride was tartar control toothpaste. The major anti-calculus strategy developed by researchers in the 1970s was to inhibit crystal growth, thus preventing the mineralization of developing plaque and the transition of the plaque into calculus. The most effective agents in vitro were the pyrophosphates, but in the oral cavity these were rapidly broken down by bacterial and salivary pyrophosphatase enzymes. In the 1980s, formulations were created using high concentrations of pyrophosphates (and other polyphosphate salts) that could be combined with sodium fluoride to both reduce tartar buildup (not preformed tartar) and retain anti-caries potency. Indeed, the concentration of sodium fluoride was high enough to serve as an anti-enzyme and help inhibit the limiting pyrophosphatases in the mouth.5 The addition of 1 percent of a copolymer of methoxy-ethylene and maleic acid (Gantrez, GAF Corp.) appears to improve the effectiveness of some anti-tartar products.6 The tartar control products that have received the ADA Seal have been shown in appropriately designed clinical studies to be effective decay preventives as well as to significantly reduce the formation of tartar above the gum line. A caveat is included on the label that such products have not been shown to have a therapeutic effect on periodontal disease. The anti-tartar ingredients are considered by both the ADA and FDA to be primarily cosmetic, not therapeutic. They do not affect the already hardened deposits.

Other anti-tartar formulations have not applied for nor received the ADA Seal. One such product, a toothpaste containing Citroxain -- a mixture of the enzyme papain, sodium citrate and alumina -- has some supporting published data and is marketed primarily as a whitening toothpaste.5 Additional anti-tartar products with supporting clinical efficacy data are available in other countries but have not been introduced in the United States. These include 0.5 percent zinc citrate combined with 0.2 percent triclosan -- an effective anti-bacterial agent;5 triclosan and the polymer Gantrez;7 and pyrophosphate and triclosan.8 The triclosan/Gantrez combination is part of a multibenefit product that has been approved by the ADA and FDA and is awaiting marketing in the United States.

Whitening Toothpastes

Virtually all toothpastes can claim stain removal and tooth brightening. Stain removal in varying degrees is a given in any dentifrice containing an abrasive and detergent and by using a properly directed toothbrush with sufficient contact time. When these elements are augmented by anti-tartar ingredients to reduce pellicle and plaque mineralization and fixation, stain removal can be enhanced. When surface stains are removed, teeth are indeed brighter and appear lighter. Tooth whitening, however, requires modifying the intrinsic tooth color, necessitating chemical alteration of the chromophores within the tooth. This process requires penetration and alteration of tooth substance. Bicarbonate, alumina and polyphosphates cannot whiten teeth; at best they can contribute to stain removal. Whitening requires bleaching or enzymatic disruption. Fortunately, the use of acid penetration and dissolution has not been an acceptable method of whitening for nearly a century.

Numerous dentifrices are now marketed with whitening claims based on the presence of various peroxides -- hydrogen, calcium or carbamide. For over-the-counter safety standards, the peroxide content should be kept low and can supply some effervescence and perhaps some very short-lived bleaching. Peroxide is rapidly broken down by oral enzymes from bacteria and saliva. Gel preparations provide longer contact time, but unless used with a tray they are usually ineffective and can be irritating. Safety is very much a concern and effective bleaching is best accomplished through an office procedure or a dentist-prescribed and approved gel formulation in an individually fabricated tray. No whitening toothpaste or over-the-counter gel has applied for or received ADA acceptance for a whitening claim. Such acceptance would require the product to meet the same safety and efficacy standards as the professional gels.

Niche Products

In addition to the basic fluoride-containing, anti-tartar and whitening dentifrices, an increasing number of niche products directed to special segments of the consumer market have been developed in recent years.

Desensitizing Dentifrices

One of the earliest of the special products was directed to people with tooth sensitivity at the gingival margin and exposed root surfaces -- an expanding segment of an aging population retaining their teeth for longer periods. Although the number of brands of desensitizing toothpastes and gels has been increasing, the basic desensitizing ingredients have remained the same -- strontium chloride, potassium nitrate and sodium citrate in a surfactant gel.4 The latter two are compatible with fluoride -- not so strontium chloride -- and ADA accepted fluoride-containing products have to have demonstrated anti-caries ability as well as desensitizing efficacy. Lately, bicarbonate has been incorporated in some products for people with a preference for this ingredient, and most recently one desensitizing toothpaste has added a tartar-control component. These combinations are meant to encourage longer use of the desensitizing paste since they also provide the benefits of regular toothpastes.

Natural Toothpastes

An increasing number of people are attracted to products that do not contain dyes or artificial preservatives or sweeteners, such as saccharine; and natural toothpastes are the beneficiaries of that trend. Part of the appeal of baking soda-containing products are their characterizations as natural. The most popular toothpastes in this category are produced by Tom's of Maine, a pioneer in this area. The company's nonfluoride toothpastes contain propolis -- a resin found in beehives that has anti-bacterial properties -- and myrrh, for gingival stimulation and astringency, according to the company. The natural toothpaste with fluoride (sodium monofluorophosphate) uses essential oils for flavor and finely ground calcium as an abrasive. It has met the requirements for the ADA Seal and has received FDA clearance.

Several herbal and herbal/bicarbonate toothpastes have been in use in Europe for a number of years. The products contain a variety of plant extracts such as echinacea, sage, camomile, myrrh and rhatany. These ingredients are claimed to have antibacterial and/or anti-inflammatory properties. There are a number of published studies on these products indicating mixed results.9,10 Similar kinds of products are available in some health food stores in this country but are not marketed nationally. The sanguinarine-containing toothpaste Viadent also uses an herbal extract but is not marketed as a natural product.

Smokers Toothpastes

Best known in the category of smokers toothpastes is Topol, which depends on a more abrasive form of silica to physically remove the heavy stains resulting from tar and resin deposits. Even such a narrowly focused product is now formulated with fluoride and has met the requirements for the ADA Seal for its gel and toothpaste. However, people with gingival recession and the resulting root exposure should exercise caution with such products because of potential damage to cementum and dentin.

Xerostomia Products

One company, Biotene, has formulated a line of products for oral care aimed at people with dry mouth due to side effects of medication, salivary gland disease (especially Sjogren's syndrome), or head and neck radiation. The products are formulated with bland flavors to be nonirritating to taste buds and soft tissues that can be hypersensitive when chronically dry. The toothpaste (and mouthwash) is theoretically designed to provide some of the natural antibacterial factors present in normal saliva that would be in short supply with deficient salivary function -- lysozyme, lactoferrin and peroxidase. Although the approach is conceptually an attractive one, there is no published data to support any significant protective claim.

Multibenefit Products

In a highly competitive dentifrice marketplace with annual sales of more than $1.3 billion, the quest for multibenefit products has been a long and rigorous one. With public recognition of the centrality of supragingival plaque in caries and gingivitis -- a recognition strongly enhanced by television advertising -- fighting plaque joined stain removal as one of the stated goals of tooth brushing. Antiplaque claims that often went beyond superior cleaning properties to specific attributes of antibacterial ingredients became commonplace. After a period of contention, the ADA took the position for its acceptance program that plaque reduction per se is not a health benefit, and it has to be accompanied by a clinically demonstrated health benefit to merit the ADA Seal. Gingivitis was the most pragmatic goal and plaque/gingivitis became the basis for a new set of guidelines. Up to now these guidelines have only been met by mouthrinses -- chlorhexidine and essential oils. The Food and Drug Administration has been moving in a similar direction for oral care products via its advisory panels.

Antiplaque/Antigingivitis

Until very recently, toothpaste products, responding to the ADA position, refrained from making direct antiplaque/antigingivitis claims based on plaque reduction or modification and settled for "fighting plaque and gum disease," or numerous variations thereof. Although overt claims were not made, the presence of particular ingredients such as sanguinarine, baking soda, hydrogen peroxide and baking soda-hydrogen peroxide combinations were projected as being of particular value. Published data does not support an antiplaque/antigingivitis claim for these products.11,12

Crest Gum Care

A new product -- actually a modernization of the original Crest fluoride toothpaste that is essentially a stabilized stannous fluoride now called Crest Gum Care -- has been marketed as an anti-gingivitis product that would be additive to the established anticaries protection of stannous fluoride.13 This product appears to have overcome some of the stability problems of the original formulation and maintains a stannous fluoride level capable of significantly reducing gingivitis. It does not achieve this added benefit by reducing the amount of plaque per se, but does affect bacterial flora and metabolic processes sufficiently -- as measured by plaque glycolysis -- to result in an impact on gingivitis.13 The reductions in a number of studies are in the 10 percent to 20 percent range with a greater reduction in gingival bleeding scores. The results are both statistically and clinically significant, as concluded recently by the Dental Products Panel, an advisory committee to the FDA. The product awaits clearance by the FDA. The new Crest stannous fluoride still retains a drawback of the original: It causes staining in some people. It does not have the ADA Seal.

Crest Multi-Care

Although marketed as a multibenefit product, Crest Multi-Care is essentially an anticaries/antitartar combination. It does not include a specific antigingivitis component and makes no claim other than "protects against mouth acids" -- a claim based on in vivo plaque pH measurements. Despite its name, it offers no therapeutic benefits beyond those of other fluoride/antitartar products. It does not carry the ADA Seal.

Colgate Total

The most ambitious of the multibenefit toothpastes to date, Colgate Total has received the ADA Seal and recently cleared the FDA's regulatory hurdles to become the first toothpaste to be approved for its ability to help prevent plaque, gingivitis and caries. Previously on sale in more than 100 countries, according to the company, Colgate Total reached U.S. consumers early this year.

Total is essentially a sodium fluoride dentifrice containing the broad-spectrum antibacterial agent triclosan (0.3 percent) and the copolymer PVM/MA (polyvinyl methyl ether malic acid), also marketed under the trade name Gantrez (2 percent). Triclosan has been used in soaps and deodorants for more than 20 years. Its broad spectrum of activity encompasses a large range of oral bacteria, and it is compatible with other ingredients in oral products. The combination of triclosan and PVM/MA inhibits crystal growth and is effective as an antitartar agent. A series of four three- and six-month clinical studies supports its value in reducing tartar formation in the range of 23 percent to 55 percent.7 The antiplaque/antigingivitis efficacy was established in 12 studies of six to seven months in duration, with plaque efficacy vs. placebo from 7 percent to 59 percent and gingivitis efficacy from 19 percent to 32 percent.7 Some recent studies strongly suggest that part of the triclosan effect on gingivitis is due to anti-inflammatory as well as antibacterial properties.14

Conclusion

Undoubtedly, additional multibenefit toothpastes currently marketed outside of the United States will become available here as well. The battle of comparative studies and advertising claims is sure to follow. It's comforting to know that although snow white teeth have been adopted as a national symbol for a dentally conscious public, oral therapeutics is not being neglected. It's not only alive and well, but thriving.

Author

Irwin D. Mandel, DDS, is a professor emeritus and was formerly asociate dean for research at the Columbia University School of Dental and Oral Surgery.

References

1. Weinberger BW, The History of Dentistry, Vol 1. CV Mosby Co, St. Louis, 1948, pp 13-40.

2. Mandel ID, Dental quackery: A retrospective view. J Am Dent Assoc 125:153-60, 1994.

3. Ramirez A, All about toothpaste. New York Times, May 13, 1990.

4. Newbrun E, Cariology, 3rd ed. Quintessence, Chicago, 1989, pp 295-313.

5. Mandel ID, Calculus update: Prevalence, pathogenicity and prevention. J Am Dent Assoc 126:573-80, 1995.
6. Schiff TG, Comparative clinical study of two anti-calculus dentifrices. Compend Cont Educ Dent (Suppl 8):S275-7, 1987.

7. Volpe AR, Petrone ME et al, A review of plaque, gingivitis, calculus and caries clinical efficacy studies with a fluoride dentifrice containing triclosan and PVMA/MA copolymer. J Clin Dent 7 (Supplement):S1-14, 1996.

8. Fairbrother KJ, Kowolik MJ et al, The comparative clinical efficacy of pyrophosphate/triclosan, copolymer/triclosan and zinc citrate triclosan dentifrices for the reduction of supragingival calculus formation. J Clin Dent 8 (Special Issue):62-6, 1997.

9. Mullally BH, James JA et al, The efficacy of a herbal-based toothpaste on the control of plaque and gingivitis. J Clin Periodontal 22:686-9, 1995.

10. Moran J, Addy M and Newcombe R, Comparison of an herbal toothpaste with a fluoride toothpaste on plaque and gingivitis. Clin Prev Dent 13:12-5, 1991.

11. Mandel ID, Anti-microbial mouthrinses: an overview and update. J Am Dent Assoc 125(Supplement):2S-10S, 1994.

12. Newbrun E, The use of sodium bicarbonate in oral hygiene products and practice. Compend Cont Educ Dent (Supplement 19):17:S2-7, 1996.

13. White DJ, A "return" to stannous fluoride dentifrices. J Clin Dent (Special Issue)6:29-36, 1995.

14. Gaffar A, Scherl D et al, The effect of triclosan on mediators of gingival inflammation. J Clin Periodontol 22:480-4, 1995.

To request a printed copy of the article, please contact: Irwin D. Mandel, DDS, Columbia University, School of Dental and Oral Surgery, 630 W. 168th St., New York, NY 10032.