Abstract-One of the major problems of fixed orthodontic treatment is controlling the enamel demineralization that occurs around the bracket. RMGIC is a modified composite resin with anti caries-effect caused by fluoride release. This study aimed to determine the effect of anti caries RMGIC as an orthodontic adhesive material through microscopic examination with SEM. Thirty maxillary first premolars were divided into two groups. One group was bracket-bonded with composite resin material and others with RMGIC. Every group was divided into 3 sub groups, each sub group was soaked in artificial saliva with a pH of 4.5 at 37° C for 7, 10 and 14 days consecutively. The bracket is de-bonded and the entire samples were then checked using SEM to find out the diameter of the carious lesion. The results showed that the mean diameter of the carious lesion in the sample using the composite resin adhesive material after soaking of 7 days was 10,77 μm±1,00, after 10 days was 19,08 μm±7,31, and after 14 days was 52,50 μm±10,69. The mean diameter of the caries lesion in the sample using RMGIC adhesive material after soaking of 7 days was 3,52 μm±1,31, after 10 days was 7,84 μm±1,66, and after 14 days was 30,04μm± 4,77. Samples using RMGIC adhesive materials resulted in smaller mean carious lesion diameter than samples with composite resin material after soaking of 7, 10 and 14 days (p<0.05). Through SEM examination, it is proven that RMGIC has better anti-caries effect compared to composite resin adhesive material.