Periodontal and dental conditions of a school population in a volcanic region of Tanzania with highly fluoridated community drinking water

INTRODUCTION: Dental fluorosis is endemic in the Rift Valley in Africa, especially around volcanic areas, due to the high fluoride content in daily drinking water. OBJECTIVE: This study evaluates the oral health status and types of occlusion in a school population, and to assess the possible association between dental fluorosis and other pathologies such as decay, gingivitis and periodontitis. MATERIAL AND METHODS: An observational study of 581 individuals recruited from a public secondary school in Arusha, Northern Tanzania was undertaken. The indices used were: the Silness & Löe Plaque Index, the Community Periodontal Index and the Decayed/Missing/Filled index. Descriptive statistical analyses were performed and a chi-square test was used to assess the associations between independent variables. RESULTS: Almost all the school children evaluated (96.73%) presented Angle class I dental occlusion, and 75.22% presented some degree of dental fluorosis. Most of the population (511, 87.95%) showed bleeding on probing. A moderate/high degree of some dental pathology (DMF score) was recorded in 14.46%. The association between dental fluorosis, gingival bleeding and tooth decay indicated a higher concentration of pathology in groups with more severe fluorosis (p<0.05). CONCLUSION: In this large population sample, both tooth decay and gingivitis were significantly associated with moderate or severe dental fluorosis.