Tooth decay is the gradual breakdown of the tooth, beginning with the enamel surface and eventually progressing to the inner pulp.
Tooth decay is caused by acids produced by certain mouth bacteria in dental plaque. Factors that affect this process include oral hygiene, diet, meal frequency, saliva production, and heredity. Teeth with significant decay are said to have caries, or cavities.
What are the symptoms of tooth decay?
People with tooth decay may have tooth pain, including sensitivity to cold food and drinks
Dietary changes that may be helpful for tooth decay
It has been noted for over 50 years that the incidence of tooth decay is low in people of traditional rural societies, such as Eskimos and African Bantus. However, However, the incidence of cavities increases as their diets begin to include more “westernized” processed foods.1 Although many different factors have been implicated in this observation, including refined flours,2 3 inactivation of vitamins by heating foods,4 and sugar intake,5 no single agent has been found responsible. Nevertheless, a diet high in whole grains and low in processed foods is a healthful choice that probably helps defend against tooth decay.
Sugar, especially sucrose (table sugar), appears to be required by the oral bacteria for the production of tooth decay. This finding has caused sugar to be widely blamed in the popular press as the primary cause of dental caries. However, caries incidence has recently declined in a time of increasing sugar intake.6 This has led to a reevaluation of caries causation, and sugar is now understood to be only one of the factors in the development of tooth decay.7 Nearly as important as the total amount of sugar intake seems to be the consistency of the sugary foods and the length of time they are in contact with the teeth. Dry and sticky foods tend to stay in contact longer, causing more plaque formation.8 Still, reduction of total dietary sugar is probably the most accepted dietary recommendation for the prevention of dental caries.9
Certain sugar substitutes appear to have anti-caries benefits beyond that of reducing sugar intake. Xylitol is not fermented by the oral bacteria, and it inhibits bacterial growth.10 Sorbitol is only slowly used by oral bacteria, and it produces less caries than does sucrose.11 Children chewing gum containing either xylitol or sorbitol for five minutes five times daily for two years had large reductions in caries risk compared with those not chewing gum. Xylitol gum was associated with a slightly greater risk reduction than sorbitol gum.12 A double-blind study found 100% xylitol gum was superior to gum containing lesser amounts or no xylitol.13 Another study found xylitol-containing gums gave long-term protection against caries while sorbitol-only gum did not.14 Other research has confirmed the anti-caries benefits of xylitol in various forms, including gum,15 chewable lozenges, toothpastes, mouthwashes, and syrups.16
Drinking fluoridated water (1 mg fluoride per liter) has led to an estimated 40 to 60% reduction in dental caries in many cities in the United States and worldwide.17 18 While most experts believe water fluoridation to be associated with minimal risk,19 others disagree. A minority of scientists believes fluoridation to be associated with an unacceptable risk of skeletal damage, including osteoporotic fractures and bone tumors, in exchange for a modest dental benefit.20 Fluoride has topical action as well as whole-body effects,21 suggesting that those who do not have access to fluoridated water can achieve some benefit with fluoride-containing toothpastes and mouthwashes. In areas without fluoridated water, a number of controlled trials have found oral use of chewable fluoride tablets (1 to 2 mg per day of fluoride)22 23 or fluoride mouthrinses (0.05% to 0.2% fluoride content)24 25 also reduce caries risk in children. Fluoride tablets26 and mouthwash27 have been found to be effective for caries prevention in young adults and the elderly. Tablets are slightly more effective than a mouthrinse for caries protection.28 These products should not be used by young children (under three years of age), who might accidentally swallow dangerous amounts of fluoride.29 The American Dental Association (ADA) recommends supplementing children in areas without fluoridated water with liquid fluoride drops,30 but this should be done with the guidance of a dentist.
Lifestyle changes that may be helpful for tooth decay
The ADA recommends regular tooth brushing—daily brushing, ideally after each meal.31 Although thorough brushing varies from person to person, five to ten strokes in each area should be adequate.32 Toothpastes containing 1,000 to 2,500 ppm (1 to 2.5 mg per gram) of fluoride have been shown to reduce caries risk.33
A recent population survey found blood lead levels were associated with the amount of dental caries in children and adults. The authors estimated that lead exposure is responsible for roughly 10% of dental caries in young Americans.34 For this and other health reasons, known and potential sources of lead exposure should be avoided. Common sources of lead exposure may include paint, foods grown near roadways, and water from lead pipes.35
Nutritional supplements that may be helpful for tooth decay
Test tube studies show that vitamin B6 increases growth of beneficial mouth bacteria and decreases growth of cavity-causing bacteria.36 A double-blind study found that pregnant women who supplemented with 20 mg per day of vitamin B6 had significantly fewer new caries and fillings during pregnancy.37 Lozenges containing vitamin B6 were more effective than capsules in this study, suggesting an important topical effect. Another double-blind study gave children oral lozenges containing 3 mg of vitamin B6 three times per day for eight months, but reported only insignificant reductions in new cavities.38
In a double-blind study of children aged 1 to 6 years, supplementation with Lactobacillus GG five days a week in milk for seven months reduced the incidence of cavities by 49%, compared with unsupplemented milk.39 The amount of Lactobacillus added to the milk was 5 to 10 x 10e5 CFU per ml.
One older controlled trial found that children given 3 teaspoons of cod liver oil per day (containing roughly 800 IU of vitamin D) for an entire school year had over 50% fewer new cavities.40 These promising results have not been followed up with modern placebo-controlled trials.
Levels of strontium in the water supply have been shown to correlate with the risk of dental caries in communities with similar fluoride levels.41 Compared with children with fewer cavities, enamel samples from children with high numbers of caries have been found to contain significantly less strontium.42 However, supplementation with strontium has not yet been studied as tooth decay prevention.
Are there any side effects or interactions with tooth decay?
Refer to the individual supplement for information about any side effects or interactions.
Herbs that may be helpful for tooth decay
Compounds present in both green tea and black tea have been shown to inhibit the growth and activity of bacteria associated with tooth decay.43 44 Animals given tea compounds in their drinking water develop fewer dental caries than do those drinking plain water.45 46 47 Human volunteers rinsing with an alcohol extract of tea leaves before bed each night for four days had significantly less plaque formation but similar amounts of plaque-causing bacteria compared with those with no treatment.48 Tea drinking has not yet been tested as a tooth decay preventative in humans.
Are there any side effects or interactions with tooth decay?
Refer to the individual herb for information about any side effects or interactions.