Self-Applied
Fluoride Toothpaste. Fluoride-containing toothpaste is the most commonly used form of self-applied fluoride worldwide.3 Fluoride in toothpaste is taken up directly by the dental plaque and demineralized enamel and also increases the concentration of fluoride in saliva.2, 3 Brushing with fluoride toothpaste increases the fluoride concentration in saliva 100- to 1,000-fold; this concentration returns to baseline levels within 1 to 2 hours.3 Fluoride toothpaste makes up more than 95% of toothpaste sales in the U.S.2The American Dental Association recommends use of a fluoride toothpaste displaying the ADA Seal of Acceptance. Fluoride toothpastes available over the counter in the U.S. generally contain a fluoride concentration of 1,000 to 1,500 ppm.2, 5, 6 Prescription-strength fluoride toothpastes contain 5,000 ppm fluoride as sodium fluoride.2, 6 In the U.S., the active ingredient in fluoride-containing toothpastes can be sodium fluoride, sodium monofluorophosphate, or stannous fluoride.5, 6
For most people (children, adolescents, and adults) brushing twice a day with a fluoride toothpaste—when you get up in the morning and before going to bed—is recommended.2 Children’s brushing should be supervised to ensure that they use the appropriate amount of toothpaste. For children younger than 3 years, parents and caregivers should begin brushing children’s teeth as soon as they begin to come into the mouth by using fluoride toothpaste in an amount described as no more than a smear or alternatively as the size of a grain of rice.3 For children 3 to 6 years of age, parents and caregivers should dispense no more than a pea-sized amount of fluoride toothpaste.3
Fluoride Mouthrinse or Gels. Fluoride mouthrinse is a concentrated solution intended for daily or weekly use and designed to be rinsed and spit out.2 The most common fluoride compound used in mouthrinse is sodium fluoride.2 The fluoride from mouthrinse is retained in dental plaque and saliva and helps prevent tooth decay.2, 3 Over-the-counter solutions of 0.05% sodium fluoride (230 ppm fluoride) for daily rinsing are available for use by persons older than 6 years of age;2, 5, 6 use in persons younger than 6 years of age is not recommended because of the risk of fluorosis if the rinse is swallowed repeatedly.3, 6 Higher strength mouthrinses (e.g., 0.2% neutral sodium fluoride to be used once a week) for those at high risk of tooth decay must be prescribed by a dentist or physician.2 Solutions of 0.2% sodium fluoride (920 ppm fluoride) are also used in supervised, school-based weekly rinsing programs.2, 3, 5
There are also self-applied gel formulations of sodium fluoride (1.1% [5,000 ppm] sodium fluoride) or stannous fluoride (0.15% [1,000 ppm] fluoride) available by prescription for home use.2, 5
Professionally Applied
Fluoride Mouthrinse, Gels, or Foams. Professionally applied fluorides are in the form of a gel, foam or rinse, and are applied by a dental professional during dental visits.2 These fluorides are more concentrated than the self-applied fluorides (e.g., 1.23% fluoride ion [12,300 ppm]), and therefore are not needed as frequently.
Because an early study7 reported that fluoride uptake by dental enamel increased in an acidic environment, fluoride gel is often formulated to be highly acidic (pH of approximately 3.0).3 Products available in the U.S. include gels of acidulated phosphate fluoride (1.23% [12,300 ppm] fluoride), as 2% neutral sodium fluoride products (containing 9,000 ppm fluoride), and as gels or foams of sodium fluoride (0.9% [9,040 ppm] fluoride).2, 5 In a dental office, fluoride gel is generally applied for 1 to 4 minutes.2, 5 Home use follows instructions provided in the package insert or as instructed by a dentist or physician.2 These higher strength products, if used in the home, must be prescribed by a dentist or physician.
Because these applications are relatively infrequent, generally at 3- to 12-month intervals, fluoride gel poses little risk for dental fluorosis, even among patients younger than 6 years of age.2, 3 Routine use of professionally applied fluoride gel or foam likely provides benefit only to persons at high risk for tooth decay, especially those who do not consume fluoridated water and brush daily with fluoride toothpaste.2
Fluoride-Containing Prophylaxis Paste. Fluoride-containing paste is routinely used during dental prophylaxis. The abrasive paste, which contains 4,000 to 20,000 ppm fluoride, might restore the concentration of fluoride in the surface layer of enamel removed by polishing, but it is not an adequate substitute for fluoride gel or varnish in treating persons at high risk for dental caries.3 Fluoride prophylaxis paste alone is not considered by the U.S. Food and Drug Administration (FDA) or ADA an effective method to prevent dental caries.3, 8
Fluoride Varnish. Varnishes are available as sodium fluoride (2.26% [22,600 ppm] fluoride) or difluorsilane (0.1% [1,000 ppm] fluoride) preparations.2, 5, 6 A typical application requires 0.2 to 0.5 mL, resulting in a total fluoride ion application of approximately 5 to 11 mg.5
High-concentration fluoride varnish is painted by dental or other health care professionals directly onto the teeth and sets when it comes into contact with saliva.2, 5, 6 Fluoride varnish is not intended to adhere permanently; this method holds a high concentration of fluoride in a small amount of material in close contact with the teeth for several hours.2 Varnishes must be reapplied at regular intervals with at least 2 applications per year needed for sustained benefit.2 Although it is not currently cleared for marketing by the FDA as an anticaries agent, fluoride varnish has been widely used for this purpose in Canada and Europe since the 1970s.2, 3 Studies conducted in Canada and Europe have reported that fluoride varnish is as effective in preventing tooth decay as professionally applied fluoride gel.2 The U.S. Preventive Services Task Force recommends the clinical application of fluoride varnish to the primary teeth of all infants and children starting at the age of primary tooth eruption.9 The recommendation is given a “B” grade, indicating that there is high certainty that the net benefit of the intervention is moderate or there is moderate certainty that the net benefit is moderate to substantial.10
According to the Centers for Disease Control and Prevention (CDC), there is no published evidence to indicate that professionally applied fluoride varnish is a risk factor for dental fluorosis, even among children younger than 6 years of age.2 Proper application technique reduces the possibility that a patient will swallow varnish during its application and limits the total amount of fluoride swallowed as the varnish wears off the teeth over a period of hours.11
Silver Diamine Fluoride. Silver diamine fluoride (SDF) is a colorless liquid that at pH 10 is 24.4% to 28.8% (weight/volume) silver and 5.0% to 5.9% fluoride.12 The FDA has classified SDF as a Class II medical device and it is cleared for use in the treatment of tooth sensitivity, which is the same type of clearance as fluoride varnish, and must be professionally applied. Although some products are commercially available in other countries, currently, Advantage Arrest™ (Elevate Oral Care, L.L.C.) and Riva Star™ (SDI, Inc.) are the only commercially available SDF products for dental use in the U.S.13 There have been reports of the use of SDF in caries control and management, although it is not specifically labeled for use for this indication (i.e., “off-label use”). Likely a result of its fluoride content, when applied to a carious lesion, SDF has been shown to lower caries risk of the adjacent tooth surface.14 SDF has also shown efficacy in management of root caries in the elderly.15-17 It likely has additional applicability as an interim approach for managing problematic caries in individuals currently unable to tolerate more involved dental treatment.18
Single application of SDF has been reported to be insufficient for sustained benefit.19 Its potential downsides include a reportedly unpleasant metallic taste, potential to irritate gingival and mucosal surfaces, and the characteristic black staining of the tooth surfaces to which it is applied.13
