Fluoridating efficiency of several fluoride-containing dentifrice systems in vivo

The primary and mixed dentition, post-eruptive enamel maturation and dental caries: a review

The mouth is in flux from the time the primary teeth begin to erupt, in the first year of life, through to the end of the 'mixed dentition' (i.e. the concurrent eruption of the permanent teeth and exfoliation of the primary teeth), at around 12 years of age. Primary teeth facilitate the development of the facial muscles and speech. They act as 'guides' for erupting permanent teeth. If lost prematurely, subsequent misalignment of permanent teeth can make them difficult to clean and possibly more caries-prone. During the mixed dentition phase, teeth are at relatively high risk of caries. Erupting teeth are difficult to clean and cleaning may be avoided because of tender gums and behavioural factors in children. Permanent enamel (and possibly primary enamel) undergoes post-eruptive maturation, accumulating fluoride, becoming harder, less porous and less caries-prone. Overall, primary teeth are more vulnerable to caries than permanent teeth. Widespread use of fluoride toothpaste has effected marked reductions in caries. Some evidence exists that fluoride delivered from toothpastes may be somewhat more effective in reducing caries in primary than in permanent teeth. However, caries remains a public health concern globally. New fluoride toothpaste formulations, optimised using in vivo fluoride delivery and efficacy studies, may improve the caries resistance of mineral deposited during post-eruptive maturation. Behaviour should not be ignored; new formulations will be more effective if used according to professionally endorsed recommendations based on sound science. Establishing good oral hygiene behaviour early in life can lead to lasting anti-caries benefits.

Evaluation of topical fluoride preparations

For practical reasons, evaluation of topical fluoride products must depend upon clinical and laboratory assessments. While not always a good predictor of clinical efficacy by itself, fluoride uptake is the most commonly used laboratory test. A consideration of the relationship between possible anticaries mechanisms of fluoride, different product types, and the meaning of various kinds of fluoride uptake data suggests that both the amount of fluoride taken up by early lesions and the amount of ambient fluoride present at a cariogenic site may play key roles in determining the efficacy of a product. While formulations applied annually or semi-annually probably depend on fluoride deposition, those used daily might not. There are no clear data supporting the superiority of one fluoride compound over another, even for infrequently used products, although there are significant differences among them in fluoride uptake by enamel. This suggests that fluoride uptake in vivo at a cariogenic site might actually be different from that suggested by in vitro data, or that larger differences are required for a clinical effect to be observable. Clinical data support the conclusion that a large increase in the fluoride concentration of a product will somewhat increase its anticaries effectiveness, although the increase will not be linearly related to concentration. There also are no obvious differences in clinical effectiveness caused by the addition of gelling agents to topical solutions. Fluoride varnishes are clinically effective but have not been shown to be superior to topical solutions or gels.(ABSTRACT TRUNCATED AT 250 WORDS)