With the advances in dental practice, oral hygienists and dentist alike have found better ways to reduce dental caries; methods that are safe and easy to apply to older patients as well as young children.

The incidence of dental caries among children in the western countries has declined sharply with the introduction of fluoride supplements. However, there is still a significant number that remains high-risk to dental caries. The decrease in caries in the occlusion areas has not paralleled those in the smooth tooth surfaces; occlusion lesions still remain persistent despite fluoride application.

Fluoride varnish

Fluorides have long been used as a means to prevent tooth decay. Measures have been made to add fluoride to water and toothpastes to meet the right amount of fluoride needed by the teeth for protection against cavities. Aside from toothpastes, Professionally Applied Topical Fluorides or PATF come in the forms of gels, foams, and varnishes. The first fluoride varnish was introduced in Germany in 1964, as Duraphat, then a similar product, Duraflor, was introduced in the United States in 1991.

Among the various types, toothpastes and varnishes are more accepted by both dentists and patients because of the ease of application. Fluoride varnish requires only a short time to apply since the dentist or oral hygienist will only paint the teeth with the solution. After which, fixation occurs in as short as 1-4 minutes, depending on the number of teeth involved. The fluoride then adheres to the teeth surface, improving fluoride uptake into the enamel and reducing demineralization.

In 2006, the American Dental Association concluded that fluoride varnishes, gels and foams were able to prevent dental caries in both the primary and permanent dentition in children and adolescents. However, fluoride varnishes are more mode of treatment as these have shorter application times and provide less discomfort, especially to pre-school children.

Indications for use

Just as in any treatment, not everyone is advised or qualified for varnish application. The treatment is recommended for those considered to have moderate- to high-risk of having dental caries. This population includes people with active orthodontic treatments (e.g. with braces), patients undergoing chemotherapy, and head and neck irradiation, those with poor oral hygiene and a high titer of cariogenic bacteria, those with in-born enamel or teeth abnormalities and defects, and those with xerostomia or dry mouth. Fluoride varnish can be applied to all age groups, and to both primary and permanent teeth, as long as there is a need to cease the progression of caries or to prevent the occurrence altogether.

Fluoride varnish application has not been found to be cost-effective against occlusion lesions or in patients at low to moderate risk for caries, who live in communities with optimal fluoridation. Also, treatment of patients with low risk for dental caries is not recommended. Asthma patients are another category not recommended for fluoride varnish applications.

Clinical Application

Application of fluoride varnish takes in to consideration the type of tooth involved, the degree of the infection, and the susceptibility of the patient to dental caries. Fluoride varnish offers an added benefit of up to 38% in children who are at high risk of dental decay. The American Dental Association has recommended that bi-annual application of fluoride varnish at 6-month intervals may be appropriate for patients aged 18 years and below with moderate risk for dental caries. Those with high risk may have applications of up to four times a year at 3-month intervals. However, the optimal frequency of applications and the optimal intervals have not been established yet.

Previously a practice, cleaning before varnish application, has now been shown to be unnecessary. Several studies have shown that there were no significant differences in caries reduction between those who underwent cleaning prior to varnish application and those patients who did not.

Varnish application is simple and can be done by a dentist or a trained assistant. The time taken for the entire process is somewhere between 3-5 minutes, depending on the number of teeth to be varnished. Teeth need not be thoroughly dried before or after treatment as the saliva helps in the fixation of the varnish.

Although there are concerns regarding fluoride toxicity, no serious side effects have been reported with properly applied varnishes. Patients and parents should be enlightened however that some fluoride varnishes will cause yellowish discoloration, which will fade away with time and brushing.