Controlled protection for milk teeth

Tooth decay in pre-schoolers is still a problem that does not only concern parents. Fluoride varnish plays an important part in keeping the deciduous teeth in young children healthy in terms of caries-preventive treatment. The advantage is that it can be applied to the teeth exactly where needed and will adhere to the tooth surfaces. Studies confirm the caries-preventive effect of fluoride varnish application on milk teeth ^[1].

Precise application

The risk-oriented application of a fluoride varnish is recommended as a caries-preventive treatment measure in young children (Fig. 1). The special properties in the varnish mean it can be used as early as the first years of life: The varnish is applied in a controlled manner onto a specific area, which then adheres to the tooth surface after drying. In comparison to other application forms, such as rinsing solutions or gels, this method bares far less risk of ingestion ^[2–4]. Studies confirm the safe use of this professional treatment method; results show the fluoride concentration, excreted in urine after a single application of the Fluor Protector S varnish by Ivoclar Vivadent, is not significantly higher than that of a placebo varnish ^[5].

How the fluoride protects

Fluoride must always be present in small amounts, so that it can inhibit demineralisation and promote the remineralisation of the enamel. This protective effect is sustained by creating a fluoride depot that releases fluoride when necessary: After applying the fluoride varnish, a calcium fluoride-like covering layer is formed on the tooth (Fig. 2). Calcium fluoride-like is a simplified description.  In addition to the main component, calcium fluoride, the varnish also contains other constituents, in particular phosphate ^[6].

Calcium ions from saliva or tooth enamel combine with fluoride ions: calcium fluoride is formed, which adheres very well to porous tooth surfaces, such as those on newly erupted tooth enamel or demineralised areas ^[7]. In a pH neutral environment, this compound is practically insoluble and can remain on the teeth for months. The denser and more evenly distributed the calcium fluoride particles cover the teeth, the better they protect against acid attacks. If the pH value falls, calcium fluoride breaks down into its constituents. These can then occupy vacant spaces in the crystal lattice of the enamel, where a more acid-resistant fluorine or fluorhydroxy apatite is produced ^[8]. In addition, fluoride ions present in saliva prevent the release of fluoride contained in the enamel and therefore reduce the risk of demineralisation.

Protection against caries

Numerous clinical studies confirm the successful caries-preventive effect of applying fluoride varnish to children’s teeth ^{[1, 3, 8, 9]}. Less tooth decay develops in milk teeth treated with an application of fluoride varnish than in milk teeth without this treatment ^[1]. An application of fluoride varnish is also successful in the remineralisation of initial carious lesions ^[10].

Risk-oriented application

Dental organizations strongly recommend the use of a fluoride varnish in patients with a high risk of caries.  For example, in children with an increased risk of tooth caries, treatment should be carried out twice a year and in patients with a very high risk, generally four to six times a year ^{[2, 12]}.

Selection criteria for a suitable fluoride varnish

The choice of a suitable fluoride varnish is not only determined by the fluoride concentration. Other properties also contribute significantly to a successful result.  In all cases, fluoride must be present and released from the varnish. A varnish system, which adheres well to the teeth and produces a dense layer of calcium fluoride, promotes the long-term release of fluoride. The preparation should not be too viscous. Only a readily flowing compound, which wets the teeth well, is capable of spreading into hard-to-reach areas quickly and easily.  A low viscous varnish will spread easily into porous, already demineralised areas, so that the fluoride can initiate remineralisation.

The varnish system, Fluor Protector S, is a product, which meets the selection criteria described above. It is a preparation in which the fluoride source, ammonium fluoride, is completely dissolved ^[13]. This enables it to be applied immediately and in a controlled dose. The latter is a particularly important aspect, especially when treating children.

The fact that the fluoride compound is completely soluble means that the fluoride itself can act directly and treat the tooth enamel instantly ^{[14, 15]}. A dense layer of calcium fluoride-like particles forms a coating over the tooth surface, which protects against acid attacks ^[15]. The comparatively tight layer creates a depot from which fluoride is released over an extended period of time.

Thanks to its flow and wetting properties, fissures, proximal surfaces and porous areas of tooth enamel can be covered equally well. This means, areas at risk in milk teeth can be protected quickly and effectively.