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Preventing Dental Caries wiith Topical Fluoride Treatment


Treatment for dental caries is expensive and poses a significant economic burden as the disease is widespread. Concerned health authorities and researchers have come up with various measures to combat dental caries by preventing its occurrence and also by reducing its impact on the quality of life of individuals and society.

In the prevention of dental caries, fluoride, besides diet has long been identified as a major factor in reducing the level of caries among children and adults for more than 60 years. Fluoride strengthens tooth surfaces and makes them more resistant to acid attacks which cause tooth decay. These effects control and prevent the development of tooth decay.

The use of fluoride in caries prevention can be divided into three categories namely community, individual and professional. Application of topical fluoride can be individual or professional.

Caries Prevention at Community Level

Fluoridation of water supply is the most successful method of fluoride delivery to the community. Fluoride from the water supply is ingested and secreted back into oral cavity through saliva. Individuals in the community also benefit from fluoride contained in foods and beverages prepared using fluoridated water.

Caries Prevention at Individual Level

Brushing with fluoridated toothpaste plays a major role in caries prevention because it combines the chemical effect of fluoride and the mechanical effect of toothbrushing in removing plaque. High concentrations of fluoride in the oral cavity not only protects the tooth surface but also enriches the residual plaque with fluoride, thus protecting the adjacent tooth surfaces.  The use of fluoridated toothpaste with fluoride content of 1000-1500 ppm is the most acceptable topical measure and also has similar effectiveness as other methods of topical fluoride application (Marinho, 2008).

Clinical Caries Prevention

Clinical caries prevention is the application of fluoride containing products by trained dental personnel on tooth surfaces.

Fluoride Varnish

Fluoride varnish was first introduced in 1960s and has become the most widely used professionally applied topical fluoride in European countries. However, usage in other parts of the world especially in Asia still confined to high and upper middle income countries like Singapore, South Korea, Hong Kong, Brunei and Malaysia (Lo, Tenuta & Fox, 2012). Fluoride varnish mostly consists of lacquers containing 5% fluoride in resin base. The resin hardens immediately after application allowing a high concentration (22,500 ppm) of fluoride to be in contact with tooth surfaces for a longer period than other methods of application. The high concentration fluoride varnish (22,500 ppm) reduces the loss of mineral from the tooth surface and also acts as a reservoir of fluoride for the oral cavity. The higher level of fluoride in oral cavity will retard and arrest the process of cavity formation.

Indications for fluoride varnish application include individuals with high caries experience, lack of exposure to fluoridated water, medically compromised and disabled individuals. Fluoride varnish has been confirmed by many studies as an effective measure to prevent caries (Marinho, 2009). These studies estimated 45%-48% reduction in caries increment when fluoride varnish was applied biannually. So biannual application is advisable for individuals with moderate risk of getting caries and for individuals with higher risk, the frequency of application should be once in three months.

Fluoride varnish is effective in both permanent and primary dentition even though the effect is more profound in permanent dentition. Fluoride varnish is also used to treat root caries among the elderly (Raghoonandan, Cobban, Compton, 2011). Application of fluoride varnish can be carried out by any trained dental personnel, not time consuming and does not require expensive extra equipment. The varnish is easy to handle and it adheres to tooth surfaces even in the presence of saliva making it the most suitable choice for young children. One drawback is that the material is more costly. However, it can be applied to specific tooth surfaces and sites so the amount used can be controlled.

Application of fluoride varnish on tooth surface

Fluoride Gel

Fluoride gel application is more common in the USA and Canada. The most commonly used gel is Acidulated Phosphate Fluoride (APF) with 1.23% or 12,300 ppm fluoride concentration. The indication for fluoride gel application is almost similar to fluoride varnish but it is usually used when the patient is wearing braces and when varnish cannot be painted directly onto tooth surfaces. There are two types of fluoride gel. The first one is applied by trained dental professionals in the dental surgery and has a higher fluoride content. The second type is for home use with a lower concentration of fluoride

The effectiveness of professionally applied fluoride gel has been documented. The frequency of application is recommended at least biannually depending on the level of caries risk. Fluoride gel application is acceptable to most patient especially adults. Some children find it difficult to tolerate the Styrofoam tray in their mouth and gagging may occur.

Fluoride Mouth Rinse

Fluoride mouth rinse is usually used as supplementary to tooth brushing especially in areas where there is no public water fluoridation. Fluoride mouth rinse should not be administered in children aged six years and below. Fluoride mouth rinse is not recommended if other methods of fluoride delivery are available.

The solution commonly used is stannous fluoride with lower concentration of fluoride (1,500-3,000 ppm) compared to gel and varnish. Sometimes it is prescribed in the dental surgery by dentists and some with lower fluoride concentration are available over the counter which is commonly used at home. Marinho (2008) noted that fluoride mouth rinsing is effective in preventing caries occurrence especially when its application is supervised. She also suggested that a combination of application of fluoride mouth rinse and toothpaste has better caries-inhibiting effect compared with the use of toothpaste alone. A local study by Chen et al. (2010) found better caries status among primary school children involved in a fluoride mouth rinsing programme and suggested weekly fluoride mouth rinse programme to primary school children in rural and non-fluoridated areas.


Topical fluoride application is not a routine procedure in dental practice. They are used for individuals with high risk of getting caries. The availability of topical fluoride products helps in caries prevention especially in areas with no water fluoridation, communities with high sugar consumption and also in under privileged societies where fluoridated toothpaste is not readily available. Its role in community caries prevention is still very limited compared to mass preventive measures like water fluoridation, fluoridated toothpaste and dental health education.


  1. Chen CJ-A, Ling KS, Esa R, Chia JC, Eddy A, Yaw SL (2010). A School-based Fluoride Mouth Rinsing Programme in Sarawak: A 3-year Field Study. Community Dent Oral Epidemiol, 38:310-314.
  2. Lo, E.C.M., Tenuta, L.M.A.&  Fox,C.H.(2012) Use of Professionally Administered Topical Fluoride In Asia. Adv Dent Res, 24(1), 11-15.
  3. Marinho, V.C.C. (2008). Evidence-based Effectiveness of Topical Fluorides. Adv Dent Res, 20,3-7
  4. Marinho, V.C.C. (2009). Cochrane Reviews Of Randomized Trials Of Fluoride Therapies for Preventing Dental Caries. European Archives of Paediatric Dentistry, 10 (3), 183-191.
  5. Raghoonandan, P., Cobban, S.J. & Compton, S.M. (2011) Scoping Review Of The Use Of Fluoride Varnish In Elderly People Living In Long Term Care Facilities. Can J Dent Hygiene, 45, No. 4, 217-222.
Last Reviewed : 23 August 2019
Writer : Dr. Aminuddin b. Mohd Natar
Accreditor   Dr. Tan Ee Hong
Reviewer : Dr. Sharol Lail b. Sujak