Chew gum, build enamel!

May 1, 2002
I look up from my exam, flustered. Who, me? How could she tell I was chewing gum?

Snap. Snap. Pop, pop, pop.

"Miss Wersel, would you please get rid of your gum?!"

I look up from my exam, flustered. Who, me? How could she tell I was chewing gum? Snap. Oh! I wasn't being disrespectful - I was building enamel! Like non-nutritive sucking, non-nutritive chewing is soothing and diverts stress. Gum is more helpful than just freshening breath, releasing stress, and looking cool. Chewing gum has been a vehicle for everything from digestive aids to a smoking replacement over the last 140 years or so.

In the early 1800s, chewing gum contained paraffin as its main ingredient. Then came chicle, and, after that, chicle with sugar. Initially, chewing gum was just sweet, but then a popcorn salesman was bright enough to add flavor to the sugar. Chicle cannot hold flavor.

In 1899, a drugstore manager contacted dentists to see what it would take to make chewing gum "tooth friendly," and Dentyne was born. The name is a contraction of dental hygiene. The history of chewing gum becomes even more interesting from there. Look it up on the Internet. In a nutshell, sugared gums are highly cariogenic to unclean teeth. Dentistry came out full force against it.

The market responded with sugar-free gums. The pressure was off! It was safe to use chewing gum again. A recent advertisement in JADA for the Wrigley product, Orbit®, claims that chewing gum increases salivary flow. Increased salivary flow - and the action of chewing - helps loosen food particles. Increased saliva relieves the symptoms of xerostomia, buffers plaque's acids, and allows for an increased rate of enamel re mineralization.

"Four out of five dentists surveyed recommend sugarless gum for their patients who chew gum." I remember thinking back when this slogan came out that it must be a trick of statistics. Since then, I have found Trident and the makers of Trident to truly be a friend to dental hygiene and dentistry.

Those in the know are aware that Trident Original and Bubblegum flavors are sweetened partly with xylitol. Xylitol is a "sugar substitute." The term is in quotes because xylitol is a sugar alcohol, and it is not made in a lab. Xylitol has been extensively studied in Europe. It does not promote decay and helps remineralize enamel - so much so that it is used in gum as part of caries-prevention programs in European school systems. The FDA doesn't quite see it that way, so no gum manufacturer can make that claim in the United States.

That did not stop Warner Lambert (now Pfizer) scientists from exploring gum as a vehicle for delivering remineralization agents. History bore out the viability of adding medicaments to gum. A sesquicentennial ago, a physician added pepsin as a digestive aid to the chicle gum already available. Today, medicine is even studying the viability of adding asthma medications to chewing gum. Recently. the scientists at the Pfizer labs introduced Recaldent™ to a line of chewing gum headed by Trident. The Trident White and the Trident for Kids brands contain this ingredient derived from the casein in milk.

The extracts of casein do not include lactose. This is where the good news begins. Over the years, scientists have looked at milk and milk products - such as cheese - for the elements of enamel remineralization. Hygienists are highly concerned about the lactose in milk being a bigger problem than the possible benefits of milk in rebuilding enamel. In clinical practice, we see the horrible disfiguring effects of babies put to bed with milk in a bottle. We don't appreciate the part of milk that helps remineralize enamel.

Hygienists know milk contains the building blocks of enamel - namely calcium and phosphate. Since they attract each other, they can bond into an insoluble complex before reaching the weakened tooth site. Australian scientists found how to keep the building blocks in suspension long enough to remineralize enamel.

Bonlae, an Australian dairy company, took the information and developed Recaldent™. Dr. Jack Vincent, formerly at Warner Lambert, caught wind of the patent originally awarded to Dr. Reynolds of Australia in the 1980s. During this past decade, Dr. Vincent designed studies to determine the viability of using the Australian technology in their gum. First, does it work? Secondly, does it have dose response - i.e., does it do more when more Recaldent™ is available. Yes, on both counts!

Pfizer developed the formulations and manufacturing capabilities to put Recaldent™ into a chewing gum product. Adding this single ingredient to gum or mints increases the rate of remineralization in a dose-response fashion over that of sugar-free gums without it. However, the bad news is Recaldent™ is expensive. So, while the company could have put more in to the confections, the market would not bear the cost. The recommended amount needed to match results according to the company's advertising is one serving (one stick, two pellets, or one mint) four times per day. Following the regimen can increase the rate of remineralization twofold over regular sugar-free chewing gum. Currently, only Trident for Kids and Trident White contain this ingredient.

Anecdotally, patients are sick to death of hearing "floss more, brush better" from their dental health-care providers. Patients that chew gum, eat candy, or drink sugary drinks hate to be asked to give up their vices. Their faces light up when given a different job to do or being asked to switch their sweets to a specific confection that actually can help their teeth. Young adolescents, especially, respond well to a perceived permission to do something fun and have it be good for them.

Watching early decay has been controversial for decades. Incipient decay must be treated, just not with a burr. The trend against surgical intervention seemed to gain favor. Lately, though, the most-favored treatment status of letting a tooth heal has seemed to fall off, possibly because of the temptation of the "watch it" mentality. The counter phrase, "Watch it do what," was born. Remineralization therapy means more than a finger-waggling lecture about brushing. Techno logically-advanced gum is a wonderful adjunct to the array of products available for this kind of therapy.

Acknowledgments: Thank you very much Dr. Doris Tancredi and Dr. Jack Vincent of Pfizer Labs for your help with this article. Other helpful sources were "The Story of Gum" by Warner Lambert, 1981, and the Internet site

Shirley Gutkowski, RDH, BSDH, has been a full time practicing dental hygienist in Madison, Wis., since 1986. Ms. Gutkowski is published in print and on Internet sites, and speaks to groups through Cross Links Presentations. She can be contacted at [email protected]