Researchers at Seoul National University, South Korea, have published “Quantitative Determination of Adhesion Patterns of Cariogenic Streptococci to Various Orthodontic Adhesives,” a study evaluating the adhesion of various cariogenic streptococci to orthodontic adhesives. Five light-cured orthodontic adhesives (one fluoride-releasing composite, three non–fluoride-releasing composites, and one resin-modified glass ionomer cement) were used. The adhesive type, bacterial strain, incubation time, and saliva coating were studied.

Thirty specimens of each adhesive were incubated with unstimulated whole saliva or phosphate-buffered saline for 2 hours. Binding assays were then performed by incubating tritium-labeled streptococci with the adhesives for 3 or 6 hours. The results showed a characteristic adhesion pattern according to the type of bacterial strains used. Streptococcus mutans LM7 showed the highest amount of adhesion, whereas S sobrinus B13 showed the least adhesion. The cariogenic streptococci adhered to the glass ionomer significantly more than to the composites, whereas there was no significant difference in the adhesion amount among the four composites. Extending incubation time significantly increased bacterial adhesion. “However, saliva coating did not significantly alter adhesion patterns of cariogenic streptococci,” SJ Ahn and his colleagues from the Seoul National University Dental Research Institute, wrote.

The researchers concluded, “This study suggests that cariogenic streptococci can adhere diversely according to adhesive type and that the adhesion of the cariogenic streptococci is not influenced by its fluoride-releasing properties.”

Ahn and colleagues published their paper in Angle Orthodontist.