Fluoride supplements and changes in tooth decay on the Island of Tristan da Cunha: 1966-1996.

BACKGROUND

The island of Tristan Da Cunha is one of the few examples in the world of a remote enclosed community. The inhabitants of the island were transported to England in 1961 as a result of a volcanic eruption and during their time in England they received a detailed dental health examination. They were later examined back on the island in 1966 by Dr John Fisher and in 1982 a school fluoride supplementation programme was introduced.

AIM

The present paper reports the results of the first dental health survey to be carried out on the island since the introduction of a regular school fluoride supplementation programme in 1982.

SUBJECTS AND METHODS

A cohort of 6-19-year-old subjects on the island were examined in 1996 using a similar protocol to that which was used by Fisher in the 1966 examination.

RESULTS

Comparing the 6-12-year-olds who were caries free in 1966 with those caries free in 1996 using the Chi-squared statistic reveals a statistically significant greater number caries free in the more recent cohort (X2 - 6.0, P- 0.014). For the older age group (13-19 years), a similar comparison reveals a highly statistically significant difference(Z2 - 12.26, P 0.005).

CONCLUSIONS

A significant increase in the number of caries free 6-19-year-old children in Tristan Da Cunha between 1966 and 1996 was noted: 1) This is a significant finding in the light of the school fluoride supplementation programme that was introduced on the island in 1982; and 2) Appropriate fluoride supplementation regimes may have conferred a protective effect in a group of children with a cariogenic diet. The paper discusses the significance of this study in the support of fluoridation as a method of reducing the prevalence of dental caries a nd also discusses possibilities for future research on the island of Tristan Da Cunha.