Award for Research in Oral Therapeutics

¹ Karolinska Institute, Stockholm, Sweden

The ability of fluorides in very low doses to reduce the number of caries lesions by over 50 percent is naturally a finding which should be elaborated and utilized as extensively as possible since dental caries is by far the most widespread of all human diseases, a disease that shows an increasing rate, especially in the developing countries, and against which the curative resources are insufficient even in the most developed countries.

There is little doubt that water fluoridation will finally become universally accepted in principle, particularly now that evidence is accumulating that its simultaneous effect on the skeleton, if any, is of a beneficial nature, stabilizing the bone tissue against osteoporosis. However, large population groups will not be able to benefit from this measure, particularly not in the so-called developing countries, where, in addition to the scarcity of piped water supplies, there is also a lack of financial and technical resources for water fluoridation. At the same time the increasing caries rate in these countries is, although not unexpected, nevertheless alarming.

There is thus no more important or worthy task for dental and allied research than the exploration of the ways, methods and effects of utilization of the unique caries-preventive power of fluorine.

A detailed knowledge of the caries-preventive mechanisms of fluorides is obviously of particular importance for any application that deviates from Nature's lesson of water fluoridation. Such applications may be of two fundamentally different types, local and systemic.

The pioneering method of local fluoride application, paintings with generally 2 percent NaF, was effective but time-consuming. In Scandinavian schools and general practice, this method has largely been replaced by fortnightly mouthwashes with weaker NaF solutions; these give about the same degree of caries reduction in schoolchildren when applied every fortnight.

From the point of view of convenient application, fluoridated dentifrices should theoretically be ideal for those who regularly use dentifrices. They provide a daily, practically automatic, local application of fluoride. With several toothpaste formulas, the clinical caries-preventive effect has been significant, but on a percentage level less than with either fluoride paintings or mouthwashes.

Systemic administration of fluoride should provide both the local effect on the tooth surfaces and the effect attained after intestinal absorption. The ingestion may be done with tablets, lozenges, drops or similar, or with common foods. Staple foods have naturally attracted interest as potential vehicles for fluoride that might lead to an automatic fluoride supply corresponding to that from drinking fluoridated water.

The dramatic effect of salt iodization against the endemic goiter in Switzerland gave a natural impetus to salt fluoridation, which has been practiced on a large scale in that country.

Fluoridation of flour or bread has been calculated to be feasible on account of the small variations in the consumption of these foods found in European countries.

Fluoridation of sugar might be said to combine the culprit and the cure of caries, but not even calculations on the variations of sugar consumption have been presented in support of this suggestion.

On the whole the supply of cariespreventive fluoride doses with staple foods combines a number of theoretical advantages with a number of scientific and practical problems (Table 1). These problems obviously necessitate extensive research, some of which will be of a universally valid nature, whereas other parts will be limited to the geographical areas where fluoride supply with a certain food is being considered.

It was natural first to concentrate scientific effort on water fluoridation, which is Nature's method and forms the fundamental of every later development. Second came the main problem of the mechanisms of the caries-preventive effect of fluorides. An early fruit of the work on this problem was local fluoride application, which has become very useful but still suffers from our incomplete knowledge of the basic mechanisms. However, concentration on complementary or, perhaps, alternative fluoride vehicles is now highly indicated. The maximal utilization of our most effective caries-preventive agent is so urgent that worldwide interest and collaboration is demanded and the greatest possible degree of coordination of the efforts should be furthered by every influential body that has the world's dental health on its program.