Background: Dental caries is a disease caused by one of the bacteria Streptococcus mutans. Prevention of caries and dental plaque can also be done by brushing the teeth regularly using toothpaste. Mechanical or chemical methods can remove plaque. Caries prevention can be done by brushing the teeth using toothpaste. Aim: To determine the effectiveness of brushing teeth with sodium lauryl sulfate toothpaste and toothpaste without sodium lauryl sulfate on reducing dental plaque index in elementary school students in Aceh Besar district. Methods: This study used a quasi-experimental method with a post-test-only group design. This research was conducted on students of elementary school students Tanjung Lhoknga, Aceh Besar district, with 120 people. Data analysis using statistical test used is Chi-Square test at 95% confidence level (= 0.05). Results: There is a difference between toothpaste with sodium laurel sulfate and toothpaste without sodium laurel sulfate (p-value < 0.05 ). Brushing teeth with toothpaste without sodium laurel sulfate had a better effect on reducing plaque index (p-value < 0.05). Brushing teeth with sodium lauryl sulfate toothpaste before the intervention, the plaque index was 1.731, and after the intervention, the plaque index was 1.562, there was a decrease in plaque by 0.169. while brushing teeth without sodium laurel and sulfate plaque index before intervention was 1,845, and plaque index after the intervention was 1,230. There was a decrease in plaque by 0.615. Toothpaste without sodium laurel sulfate lowers plaque index more than toothpaste with sodium laurel sulphate. Conclusion: Brushing teeth with toothpaste without sodium laurel sulfate is more effective in reducing plaque index.