Supplementary Material for: Association between a New Sugar Index and Caries Experience: Results of a Cross-Sectional Field Study

Objectives: The aim of this study was to test the relationship between a newly developed sugar index and caries experience in 4th- and 6th-graders. Materials and Methods: A total of 1,019 fourth-graders and 925 sixth-graders from 2 regions in Northern Germany participated in the study. Caries experience was recorded by applying the ICDAS criteria. Tooth-brushing habits and other independent variables were examined psychometrically. Structured questions were formulated that were related to specific everyday eating situations, especially between main meals, which proved to be relevant for a higher caries risk. To compare mean caries scores, nonparametric tests were applied. The Pearson coefficient was calculated in order to verify the correlation between the sugar index and the caries experience. The influence of various independent variables on caries experience was assessed by stepwise backward logistic regression analysis. Results: With regard to the primary teeth of the 4th-graders, significant correlations with values > 0.1 were found for all ICDAS outcome variables. With regard to the permanent teeth of the 6th-graders, the only significant correlations with the sugar index were for the ICDAS outcome variables D_3–6MFT and D_3–6FS. Conclusion: The results of our study show that not only the correlation between the sugar index and caries experience was stronger for 4th-graders than for 6th-graders, but also more distinctly visible differences were observed when comparing extreme groups. This indicates that protective factors, such as fluoridation and the preventive sealing of fissures, help level out the differences in caries occurrence in older children when compared to younger children.