Statistical analysis
carious lesion, caries, tooth
REGRESSION, CARIES
Data were analyzed using SPSS version 26.0 for Windows (SPSS Inc., Chicago, IL, USA). The level of statistical significance was set at An intention-to-treat analysis was performed. The carious lesion status of the drop-out participants or participants who received restorative treatment or extraction between follow-up visits were recorded as caries development. The Chi-square test was used to analyze the effectiveness of topical fluoride agents in preventing approximal caries development and the association of other variables on approximal caries development. Since more than one approximal surfaces were chosen from one tooth and one child, the multi-level logistic regression analysis was performed to assess the relative effectiveness of topical fluoride agents in preventing approximal caries development at the 18-month follow-up. Effects of potential variables, including baseline demographic background, oral health-related habits, baseline clinical characteristics, on approximal caries development were also evaluated by this analysis.