Sealing and fluoride

Cleaning removes what is there. Sealing and fluoridation change the tooth itself — they make it less vulnerable. Both are short, painless measures, and for children and adolescents both are part of what the statutory health insurer covers.

Fissure sealing

The chewing surfaces of the molars are not smooth. They bear a pattern of grooves and pits, the fissures. Some are so narrow that no bristle reaches into them — plaque can stay there even if brushing takes place. That the chewing surfaces are the most common site of caries in children has exactly this reason.

In sealing, the groove is cleaned, the surface roughened with a gel, rinsed and dried, then a flowable resin is introduced and hardened with light. The groove is afterwards filled and smooth. Nothing is ground away and nothing is anaesthetised; the appointment takes a few minutes per tooth.

When and for which teeth

The sensible moment is shortly after the tooth comes through, because the fresh enamel has not yet fully hardened and is particularly vulnerable in this phase. The first permanent molars come at about six years of age, the second at about twelve.

The statutory health insurer covers the sealing of the four permanent molars up to the 18th birthday. Further teeth — premolars or deep pits on front teeth — are a private service; whether it is necessary is decided by the findings.

How long does it last

Several years, but not indefinitely. It can come away in part, and a half-detached sealing is worse than none, because plaque gathers under the margin. It is therefore checked at every examination and topped up where needed. Adults as a rule no longer need sealing: the enamel is mature, and the grooves have been rounded off by chewing.

Fluoride at the practice

Fluoride is the most effective single measure against caries that dentistry has available. It works in three ways: it builds into the enamel surface and makes it more resistant to acid, it promotes the re-deposition of minerals into incipient decalcification, and it inhibits the metabolism of the bacteria in the plaque.

What matters here is that fluoride works locally — on the tooth surface, not through the bloodstream. That is why toothpaste is the most important source, and why varnish and gel at the practice complement it rather than replace it.

Varnish, gel and solution

• fluoride varnish is highly concentrated and adheres for several hours. It is used with children at the early-detection appointments and at individual prevention, on sensitive tooth necks and on incipient decalcification. With children at increased risk, several times a year.
• Fluoride gel is applied in a tray or with a swab. There are preparations for the practice and weaker ones for home, usually once a week.
• Fluoride solution for rinsing is the weakest form and a sensible addition for people with a brace or at increased risk.

How much is too much?

Too much fluoride is an issue during tooth formation, not afterwards. If a small child takes in considerably more than recommended over a longer period, white spots can appear on the later permanent teeth. What follows from this is not abstinence but a stated quantity: for small children a rice-grain-sized amount of toothpaste, from the second birthday a pea-sized amount — and keep the tube out of their reach.

For adult teeth this danger does not exist. Anyone who uses a fluoride toothpaste, has a varnish twice a year and applies a gel weekly is within the intended range.