You Are What You Eat

Carbonated beverages are now the most commonly consumed drinks in the United States.¹ Another popular trend is “grazing” or eating five to six small meals a day for weight loss and overall health. What connects these two seemingly unrelated facts? The potential for tooth wear is the link.

Eating habits may unknowingly contribute to tooth wear, dentin hypersensitivity, and caries. The health of oral tissues are also affected by nutrition, diet, and food habits. Thus, oral health professionals must take a proactive approach by including dietary and nutritional counseling as part of an overall dental hygiene treatment plan.

DIET AND ITS EFFECT ON TOOTH WEAR

All patients should be considered at risk for developing tooth wear. Dental examinations should include looking for the clinical signs of tooth wear in addition to inquiring about dietary habits. Tooth wear is a multifactorial condition leading to the loss of enamel and dentin, which can lead to dentin hypersensitivity and caries.² Tooth wear caused by acid erosion can result in demineralization, where minerals—primarily calcium and phosphorous—are dissolved from the tooth structure by acids formed by mutans streptococci and lactobacilli.³ Food plays an important role in this process.

Carbohydrates in particular can adhere to acid-forming bacteria, which immediately break down sugar to form an acid, thereby lowering the pH levels in the mouth. Before eating, pH levels are within the range of 6.2 to 7.0. Immediately following the intake of carbohydrates, pH levels drop rapidly. The longer pH levels drop, the higher the risk of demineralization. The average pH required for enamel demineralization is between 4.5 and 5.5 and for root surfaces it is between 6.0 and 6.7.³

The frequency of meals plays a role in demineralization due to the drop in pH levels after carbohydrates are consumed. In patients who eat frequently throughout the day, the teeth do not have the opportunity to remineralize between meals. The amount of food consumed is not as important as how often or how long the tooth is exposed.

Drinking soda is another risk factor. The average person drinks more than 56 gallons of soda per year, which translates into more than 1.5 12 oz cans of soda every day.⁴ One can of soda contains approximately 10 teaspoons of sugar and has a pH level of 2.7-3.5 (see Table 1 for pH levels of popular foods and beverages). Some soda drinkers compound the problem by swishing the soda around in the mouth, lengthening the soda’s exposure time to the tooth surface. Prolonged soda exposure causes the lowering of the pH level for an extended period of time, furthering the risk for tooth wear damage. For this reason, patients who drink soda should drink quickly rather than take small sips over a long period of time

Once lowered, 1 to 2 hours are required for pH levels to return to normal.³ However, patients can shorten this time by activating their saliva to buffer the effects of food, as well as to remove cariogenic foods more promptly. Drinking water to rinse the mouth immediately after eating is recommended in addition to the daily use of fluoride either through water, foods, dentifrices, or rinses to manage the risk of demineralization. Snacks such as crackers, dry cereal, pretzels, raisins, and bananas may seem harmless but these foods are highly retentive fermentable carbohydrates and have a tendency to linger in the oral cavity for a longer period of time while decreasing pH levels.

DENTIN HYPERSENSITIVITY

In addition to tooth wear, dentin hypersensitivity may also be caused by extrinsic factors, including the consumption of acidic foods and carbonated beverages, sports drinks, red and white wines, and citrus fruits.⁵ Some of these same items may lead to erosive effects that remove dentin and/or the smear layer—opening tubules that are susceptible to outside stimulus. Intensity of the pain can vary from day to day and person to person, however, it often is triggered by foods and beverages.

Dentin hypersensitivity can affect people at any age. However, those between the ages of 20 and 50 report dentin hypersensitivity more frequently. This is especially true for individuals between the ages of 20 and 30.⁶ As people age, mineralization occurring naturally over time may block or interrupt the pain-causing stimulus, thereby decreasing incidences of dentin hypersensitivity.⁷ In addition, dentin hypersensitivity appears to be more prevalent in women than men.

Dental hygienists need to inquire about a patient’s food habits at every visit to better educate the patient on the effects of food and to uncover undiagnosed dentin hypersensitivity. In some cases, dental professionals can ask patients to keep a food diary for 3 days prior to the appointment in order to obtain information about their diet. However, this may not be realistic in many private practices. In either circumstance, the following questions can begin a dialogue:

1. What types of foods do you consume on a daily basis?
2. Are your food choices acidic, such as citrus foods or carbonated beverages?
3. Are you a frequent consumer of carbohydrates like chips, crackers, and/or cereal?
4. Do you avoid any specific foods or beverages that cause tooth sensitivity or pain?
5. Do you experience discomfort from cold or hot foods or beverages such as ice cream or coffee?
6. Do you experience discomfort from foods or beverages that are acidic, such as tomato products or fruit juices?

Patients can learn to prevent dentin hypersensitivity and caries by making some lifestyle and diet adjustments. For example, a simple recommendation for treating symptoms of hypersensitivity is the twice daily use of an over-the-counter desensitizing fluoride toothpaste containing 5% potassium nitrate. Not only do patients receive the benefits of potassium nitrate, but they also benefit from the fluoride.

Some degree of tooth wear occurs within a lifetime but in some individuals, the wear reaches pathological levels.⁸ Hygienists can help patients prevent such conditions through early intervention of both tooth wear and dentin hypersensitivity to avoid major dental restorative challenges. Common patient treatment recommendations are:

• Reduce frequent exposure to both regular and diet soft drinks and juices;
• Avoid any tooth wear-inducing habits such as sipping, swishing, or holding drinks in the mouth;
• Cut down on the frequency of between-meal sweets. Avoid using slowly dissolving items like hard candy and cough drops;
• If drinking an acidic drink through a straw, ensure the flow is not aimed directly at any individual tooth surface
• Eat more non-decay promoting foods, such as low-fat cheese, raw vegetables, nuts, popcorn, and bottled water; and
• Use a soft toothbrush and low abrasion dentifrice with potassium nitrate to minimize any additional tooth wear.⁵

Fortunately, hygienists are in the optimal position to discuss the presence of tooth wear, dentin hypersensitivity, and caries. Because dietary habits may lead to any one of these conditions, all patients should be considered at risk and should be examined with this in mind.

REFERENCES

1. American Beverage Association. What America’s Drinking. Available at: www.ameribev.org/variety/ what.asp. Accessed February 3, 2006.
2. Bartlett DW. The role of erosion in tooth wear: aetiology, prevention and management. Int Dent J. 2005;55(4 Suppl 1):285-290.
3. Wilkins EM. Protocols for prevention and control of dental caries. In: Clinical Practice of the Dental Hygienist. 9th ed. Philadelphia: Lippincott, Williams, & Wilkins; 2005:393-401.
4. Erickson PR, Alevizos DL, Rindelaub. Soft drinks: hard on teeth. Northwest Dent. 2001;80:15-19.
5. Zero DT, Lussi A. Erosion—chemical and biological factors of importance to the dental practitioner. Int Dent J. 2005;55(4 Suppl 1):285-290.
6. Gillam DG, Aris A, Bulman JS, Newman HN, Ley F. Dentine hypersensitivity in subjects recruited for clinical trials: clinical evaluation, prevalence and intraoral distribution. J Oral Rehabil. 2002:29:226-231.
7. Daniel S, Harfst S. Dentinal sensitivity. In: Mosby’s Dental Hygiene 2004 Update: Concepts, Cases and Competencies. Philadelphia: Mosby; 2004:429-439.
8. Addy M. Dentine hypersensitivity: New perspectives on an old problem. Int Dent J. 2002;52:375-376.

From Dimensions of Dental Hygiene. April 2006;4(4): 20-22.