A Chemical Approach to Optimizing Bioactive Glass Dental Composites

The chemical microenvironment surrounding dental composites plays a crucial role in controlling the bacteria grown on these specialized surfaces. In this study, we report a scanning electrochemical microscopy (SECM)–based analytic technique to design and optimize metal ion-releasing bioactive glass (BAG) composites, which showed a significant reduction in biofilm growth. SECM allows positioning of the probe without touching the substrate while mapping the chemical parameters in 3-dimensional space above the substrate. Using SECM and a solid-state H+ and Ca2+ ion-selective microprobe, we determined that the local Ca2+ concentration released by different composites was 10 to 224 µM for a BAG particle size of 2+ was determined to be maximal for particles 7 µm3 for BAG-resin composites and (1.29 ± 0.53) × 107 µm3 for resin-only composites. This study thus lays the foundation for a new analytic technique for designing dental composites that are based on the chemical microenvironment created by biomaterials to which bacteria have been exposed.