[The influence of Streptococcus sanguis on corrosion resistance of magnetic retainer]

To study the effect of Streptococcus sanguis on corrosion resistance of magnetic retainers in which are encapsulated with stainless steel artificial saliva.A magnetic retainer was put in one culture flask,which was filled with artificial saliva.Ten of them were added Streptococcus sanguis suspension,the others were added PBS as control.The culture flasks were cultivated in incubator(36 degrees centigrade). 5 ml suspension was dislodged from each flask at the 3rd, 10th and 20th day. The quantity of Fe(3+) and Mn(2+) was detected.Statistical analysis of paired t test was performed with SPSS10.0 software package.When Streptococcus sanguis existed, the quantity of Fe(3+) and Mn(2+) was significantly higher than that in the control (P0.01).The existence of Streptococcus sanguis destroys the corrosion resistance of magnetic retainers remarkably.