At what age should professionally-applied topical fluorides first be administered?

More than just a patient's age should be considered in determining the treatment regimen. A fluoride history should be taken on each patient and the decision based on: age; caries (tooth decay); level of water fluoridation; and additional fluoride exposure.

For most children, topical fluorides can be applied beginning at age three. In active and rampant caries groups, some clinicians have recommended topical applications as soon as the teeth erupt. Due to the porosity of newly erupted teeth, the primary dentition receives even greater anticariogenic benefits from fluoride than does the permanent dentition.

When topical applications are begun at an early age, precautions should be taken. These include: close monitoring of the amount of fluoride used; adequate evacuation during treatment to prevent ingestion; and thorough expectoration following treatment.

In addition to office fluoride application, what other therapies should be used?

Studies have shown that multiple fluoride therapies produce superior results. The most beneficial regimen uses a systemic mechanism (water fluoridation or dietary supplementation) and as many topical approaches as needed to control caries.

Twice-a-year office topical applications provide infrequent high concentrations of fluoride. Dentrifices (toothpastes), mouth rinses and home fluoride gels offer frequent low concentration which is needed to enhance the remineralization process of the tooth enamel.

What is remineralization and how does it work?

The process of tooth decay causes demineralization or loss of minerals. With the aid of fluorides, minerals can be incorporated back into the lesion through remineralization. Both the demineralization and remineralization processes are continuously ongoing within the tooth. When remineralization overcomes the demineralization process, caries (decay) can actually be reversed and the lesion repaired. The remineralization process also significantly increases the size of the enamel crystals. These larger crystals are more resistant to acid attack than even natural enamel.

These processes are occurring in the tooth subsurface. Unfortunately, dental professionals are unable to detect early subsurface lesions even on the best of radiographs. It is usually not until the lesion has spread into the dentin, the second layer of tooth structure past the outermost enamel, that it becomes radiographically detectable. At the point where a lesion becomes barely detectable, scientists estimate that it has been developing for approximately 36 months.

Therefore, individuals that were once considered "caries-free" should now be recognized and treated with fluorides which will help reverse the undetectable subsurface destruction. Research has shown that low level fluorides (such as contained in dentifrices (toothpastes), rinses, and home fluoride gels) are more effective than high fluoride concentrations from the standpoint of enhancing the remineralization process.

Should dental professionals recommend fluoride therapy for adults?

Though there have been few studies which specifically focus on adults, systemic and topical fluorides can provide significant benefits. It has been assumed that children are in greater need of fluorides because of their higher caries rate ... but adults are not caries-free. Adults with undetectable subsurface or "white spot" lesions can benefit from the increased remineralization potential of continuous low fluoride levels. Also, the growing incidence of adult root caries could be reduced through utilization of office and home fluoride regimens.

Can fluorides benefit xerostomic (dry mouth) patients?

When salivary flow is absent or minimal, caries destruction is rapid and rampant. Patients experiencing drug or radiation-induced xerostomia (dry mouth) should be treated with professionally-applied fluorides, home fluorides, and a strict program of oral hygiene.

A complete health history must be taken to consider previous conditions and drug exposures. Temporary dry mouth commonly occurs as a side effect of many drugs including: antihistamines, diuretics, antihypertensives, anticholinergic, antidepressants, antipsychotics, and decongestants.

Salivary gland dysfunction can be caused by radiation exposure of the head and neck. This permanent xerostomic condition represents a lifelong high caries risk requiring the frequency of exposure provided by daily home fluorides and in some cases, artificial saliva preparations.

Does fluoride possess anti-plaque properties?

In addition to decreasing enamel solubility and enhancing the remineralization process, fluoride has been shown to affect the metabolism and quantity of plaque bacteria. Both high and low concentrations of fluoride could be useful as an adjunct to traditional mechanical plaque control therapy. Most of the research in this area has used stannous fluoride which has demonstrated the ability to metabolically disrupt plaque bacteria-specifically, Streptococcus mutans.