How to Manage Patients With High Caries Risk Using Nonsurgical Treatment and Bacteria-Repelling Composite

A new approach for addressing recurrent caries is the use of antibacterial restorative materials incorporating quaternary ammonium compounds (QACs). QACs are positively charged molecules that are attracted to the negatively charged cell walls of bacteria. A long chain of the QAC can bind to and penetrate the bacterial cell wall and cause leakage of its cytoplasmic contents. Therefore, the mechanism of action of QAC-containing materials is a “contact kill.” QAC molecules have been incorporated into silica filler particles, known as QA silica (QASi) particles. Currently, the only commercially available resin composite containing these QASi particles is Infinix (Nobio Ltd).