Adherence of Streptococcus mutans to orthodontic brackets.

The affinity of Streptococcus mutans to orthodontic brackets made from metal, plastic, and ceramic was tested. Twelve saliva-coated brackets and 12 noncoated brackets of each type were immersed in a S. mutans solution labeled with [3H] thymidine. Each sample was then immersed in distilled water at 20 degrees C for 24, 48, and 72 hours to measure the adherence of S. mutans to these samples. During the first 24 hours, the adherence of S. mutans decreased with and without saliva coating. Between 24 and 72 hours, the adherence of S. mutans to the saliva-coated brackets remained unchanged; the adherence to uncoated brackets showed a decrease. Saliva coating caused a decreased affinity of S. mutans for all products tested. The initial affinity of S. mutans to metal brackets was statistically significantly lower than that to plastic and porcelain brackets with and without saliva coating.