Long-Term Antibacterial Effects of Different Orthodontic Cements

The purpose of this study was to evaluate the antibacterial properties of different orthodontic cements using a direct contact test (DCT). Materials and Methods: The antibacterial properties of 6 orthodontic cements were evaluated with DCT. For the DCT, wells (n=8) of 96-microtiter plates were coated with the tested cements (Durelon, Ketac-Cem Radiopaque, GC Fuji Ortho Band LC Paste Pak, Meron, Ultra Band Lok, and 3M Unitek Multi Cure). A Streptococcus mutans suspension was placed on the surface of each specimen for 1 hour at 37 degrees C. Bacterial growth was monitored for 16 hours with a temperature-controlled microplate spectropho-tometer. The kinetics of the outgrowth in each well was recorded continuously at 650 nm every 30 minutes. Additional experiments were performed in which the tested materials were aged for 1 week, 1 month and 3 months. The data were analyzed by one-way ANOVA, and Tamhane's T2 multiple comparison test. Results: The results of the DCT showed that, freshly mixed samples of 3M Multi Cure (P=0.02), GC Fuji Ortho (P=0.04), Meron (P=0.001), and Durelon (P=0.001) showed antibacterial activity. After aging for one week 3M Unitek Multi Cure (P=0.000), Durelon (P=0.03) still showed antibacterial activity. In the experiments with 1 month aged specimens, only Durelon (P=0.001) showed antibacterial activity. In the 3 months aged specimens, 3M Multi Cure (P=0.000), GC Fuji Ortho (P=0.001), and Durelon (P=0.001) showed antibacterial property. Conclusion: Within the limitations of this study, 3M Unitek Multi Cure, GC Fuji Ortho, and Durelon, showed antibacterial properties during study period.