Maintaining a healthy set of teeth and gums is a goal pretty much everyone shares. For this special wellness issue, three Asheville-area dentists share some of their wisdom about the best ways to build strong teeth, prevent cavities and generally take good care of your choppers. Their recommendations range from regular brushing and flossing, limiting sugary foods and drinks, and using either fluoride-containing or alternative dental products to strengthen tooth enamel.
Dr. Kani Nicolls, a dentist who’s practiced in Asheville for over 20 years, explains that a big part of dental health comes down to a tiny but complex ecosystem of bacteria. “There are at least 700 different kinds of bacteria in our mouths,” she says. When those bacteria stick to one another and to teeth and gums, she continues, they create a “biofilm.” Even though it might not sound like it, that can be a good thing. “In a healthy biofilm the good bacteria keep the bad bacteria in check,” Nicolls says.
But without proper oral hygiene, the biofilm can take a turn to the dark side. In the absence of regular brushing and flossing, or if a person consumes a lot of sticky, sugary foods, the bad bacteria can overwhelm the good, Nicolls explains. When that happens, the bacteria mutate into a new form that secretes acids. Those acids can damage tooth enamel, leading to cavities and gum disease.
In addition to brushing, flossing and avoiding sugars, Nicolls says there are other ways to neutralize the acids that attack your teeth. Saliva contains bicarbonate, an alkaline substance that helps with normalizing the mouth’s pH after eating. Drinking water throughout the day or chewing sugar-free gum can help keep the salivary glands flowing, Nicolls says.
Another aid Nicolls recommends is sugar-free chews that contain the alkaline substances arginine, bicarbonate and calcium carbonate. In addition to the ingredients that neutralize acid, the calcium in the chews helps strengthen tooth enamel.
Oral probiotics can also serve as an ally in what Nicolls describes as a benign form of germ warfare. Studies have found that people with healthy mouths have a distinct culture of oral bacteria. So researchers have analyzed the composition of the healthy biofilms in those people and replicated it in a probiotic product, Nicolls says.
As a college chemistry major, dentist Dr. Mark Knollman says he learned, “If your goal was to destroy teeth, you would take a mild acid and sugar and put them together in a container and say, ‘Drink this.’ And it would rot your teeth out.”
Based on that lesson, Knollman continues, he assumed during the early years of his career that those who formed cavities were eating large amounts of candy, cookies and cake. Now, after 28 years practicing dentistry, he says, “I don’t find many patients where that’s really the problem. Those are actually very few and far between.” The larger culprit, he explains, is the sugar people consume in liquid form.
In addition to sweetened sodas’ high sugar content, Nicolls says, these beverages generally include some combination of citric, carbonic and phosphoric acids.
“One sip of a soft drink can lower the pH in your mouth for up to four hours,” Knollman reveals. Therefore, people should limit sugary drinks as much as possible, he advises, noting that “water is healthy and cheap.
“For a lot of people that’s a big stretch — for them to switch from soft drinks to water. One option is to switch them to diet drinks. I’m not a big fan of artificial sweeteners because they come with their own set of problems, but they are slightly better for your teeth,” says Knollman.
The average 12-ounce can of soda contains over eight teaspoons of sugar. But ferreting out just what kinds and how much sugar a product contains can be challenging. Fructose, glucose, dextrose and maltose are just some of the names for sugar that show up on product labels, says Knollman. “The average consumer just isn’t educated about appropriate sugar portion sizes to understand how it impacts their overall health.”
How about fluoride?
Fluoride’s role in promoting dental health has been the subject of significant public attention — and controversy — since the U. S. first began introducing the chemical into public water systems in the 1950s.
Fluoride, Knollman explains, strengthens teeth by chemically changing the makeup of the tooth’s enamel. Natural, unsupplemented tooth enamel is made of a chemical crystal called hydroxyapatite, he says. The first part of that crystal, the hydroxide ion, can be replaced with a fluoride ion, creating a new crystal, fluorapatite — a substance that’s harder and “a lot more resistant to acid attack,” according to Knollman.
But the extent of remineralization can only go so far, he continues. “You can’t make it twice as hard by giving people twice as much fluoride.”
Though fluoride is toxic at higher doses, the federal Food and Drug Administration does not regulate the substance at 1 part-per-million, the amount added to public drinking water supplies. At the same time, fluoride is also not regulated by the Environmental Protection Agency, which suggests appropriate levels for drinking water, since the substance is introduced during the treatment process rather than added directly to a body of water. The Centers for Disease Control and Prevention provides public education for fluoride uses.
All water is local
Since no one federal agency holds responsibility for adding fluoride to public water systems, the decision to fluoridate or not is made at the local level.
Asked about his position on Asheville’s fluoridation practices, local dentist Dr. Phil Davis referred Xpress to a summary of his concerns about water fluoridation in a Sept. 18, 2015, editorial in the Asheville Citizen-Times. “Exposure keeps adding up,” Davis wrote. “Fluoride has been added to toothpastes, mouthwashes, tooth sealants and other dental products. It’s in processed foods, commercial beverages made from fluoridated water, pharmaceuticals, pesticides and cigarette smoke. Today we know that nearly all of fluoride’s effect occurs via surface contact to teeth. Swallowing is not necessary. When fluoride is swallowed, healthy kidneys excrete about half. The remainder accumulates in the body over time.”
Critics of fluoridation point to a list of adverse health impacts of the long-term accumulation of the substance in the body, which they say include dental and skeletal fluorosis, lower cognitive function in children, hyperactivity disorders, and thyroid and other endocrine system disruptions.
Concerns also surround the type of fluoride used in community water treatment. The Asheville Buncombe Food Policy Council asked Asheville Mayor Esther Manheimer to stop adding fluoride to the local water supply in June 2015 (“Food Policy Council Urges Asheville to Stop Fluoridating Water,” Sept. 9, 2015, Xpress). In a letter, the ABFPC outlined its concerns: “The chemicals used to fluoridate water are not pharmaceutical grade (sodium fluoride). The form of fluoride added to the city water supply is hexafluorosilicic acid and is obtained from a chemical plant located in Spruce Pine. Industrial-grade fluoride chemicals are classified as hazardous wastes and may be contaminated with various impurities, including arsenic.”
The ABFPC’s letter contends that by putting fluoride in the water “the dose cannot be controlled, as people ingest varying amounts of water. This is of particular concern for infants and young children and especially those consuming infant formula made with fluoridated water. Infants who receive formula made with fluoridated water … may receive an estimated 175 times more fluoride than a breast-fed infant.”
Starting them young
According to the CDC, children under 8 years of age can develop a condition known as “dental fluorosis” from overexposure to fluoride while the permanent teeth are still developing under the gums. In its milder forms, the condition may appear as scattered white spots or thin white lines on the surface of a tooth. More severe forms can result in larger white patches or, rarely, a rough and pitted tooth surface. Once permanent teeth have erupted, the risk of dental fluorosis is past.
Those who wish to opt out of fluoridated public water supplies can use water from springs, wells or other untreated water sources. Pitcher and tap-style water filters don’t generally remove fluoride from water. Reverse osmosis whole-house water treatment systems can remove the substance, but they are costly.
To minimize fluoride exposure, some people use fluoride-free toothpastes that contain xylitol, a sugar alcohol that reduces plaque on tooth surfaces. Other alternative tooth products contain calcium and phosphate, which manufacturers say also strengthen tooth enamel.
Despite the controversy surrounding fluoridation in public water supplies, Knollman says he thinks the use of fluoride has had significant public health benefits. “I have made a career basically out of taking care of baby boomers,” he says, “people who grew up pre-fluoride, and they have a ton of cavities.”
By contrast, he continues, “Now I see a bunch of people under 40 who think the dentist is just a place where you get your teeth cleaned and you get a free toothbrush twice a year. … So this is my empirical evidence that fluoride has benefited this generation.”
While Nicolls says she respects the preferences of her patients who wish to avoid fluoride, she is on the same page as Knollman when it comes to the oral health benefits of fluoridation. “I don’t think that oral hygiene is any better now than it ever was,” she confides. “But I think the kids that have fluoride are definitely more resistant to cavities.”
Nicolls recommends establishing oral care habits when a child’s first tooth appears. “As soon as children’s teeth begin to come in is the time to brush and clean them and begin healthy, positive dental experiences,” she advises. Parents shouldn’t wait until something hurts or a problem arises, she continues. “It is all about developing positive habits and a healthy oral health program.”