Evaluation of Adhesion of Streptococcus Mutans to Ceramic, Metal ;pland Self-ligating Brackets

Adhesion of bacteria to orthodontic brackets depends on several factors. The design and the properties of the brackets seem to have a significant effect on the adhesion of S mutans, especially in adult patients. Therefore, in order to examine the influence of different orthodtonitc bracket materials and bracket designs (metal, ceramic and selfligating) on growth and adhesion of streptococcus mutans, this study was designed. Materials and Methods:This experimental in-vitro study was performed on 60 sample of three types ofbrackets (metallic, ceramic and self-ligating). Each bracket was placed inside a plate containing 15ml of sterilenutrient broth medium with 20% sucrose. Then to each plate 5ml of bacterial suspension was added. Plates were incubated for 5 days at 37? Celsius. After removal of theliquid medium of nutrient broth, then the plates were kept upside downed for a day, and then the number of colonies attached to the plates were counted by eye and expressed by Colony forming unit (CFU). The next phase of testing was done to confirm the first stage. At this stage brackets were removed from the plates and then placed inside the Blood Agar medium. Once again the colonies were counted. The data were analyzed by ANOVA test. Results:In this study three types of brackets was used. The maximum adhesion of S. Mutans was seen on Self-ligating brackets (25.51 ? 01.15), followed by classical twin metal brackets (8.21 ?1.7) and the minimum adhesion was in relation to Ceramic brackets (5.15 ? 6.3). A similar results was also recorded for the brackets that were placed in the Blood Agar medium (p