RESUMEN
In a retrospective study in two different regions of Germany, 1,041 fifteen-year-old pupils were examined for dental fluorosis. The adolescents had taken part in different caries prevention programmes. There were 746 subjects in the study group and 295 subjects in the control group. For each participant, specific aspects of early development, diet and fluoride exposure in group prevention programmes and at home were determined by means of questionnaires. The Thylstrup-Fejerskov index was used to classify the fluorosis scores on the buccal surfaces of teeth 11, 12, 13, 14, 15 and 16 after compressed air drying of the teeth. Binary logistic stepwise regression analyses were conducted to identify associations between fluorosis and potential influence factors. A distinction was made between early and late developing tooth parts. The significance level was set at alpha = 0.05. Fluorosis prevalence in the regions studied was 7.1 and 11.3%, respectively. The difference was not statistically significant (p = 0.052; chi square). Binary logistic stepwise regression analysis revealed that 'early start of toothbrushing' was a statistically significant predictor of dental fluorosis in the early-mineralizing enamel (OR = 1.99, p = 0.027). For the late-mineralizing enamel no single independent variable was identified as a significant predictor of dental fluorosis.