Enhancing Early Enamel White Spot Lesions Management: Effects of Ag–Sr Codoped Mesoporous Bioactive Glass on Remineralization and Antibacterial Activity

White spot lesions (WSLs) pose a persistent clinical challenge requiring materials that address remineralization and bacterial control. Here, Ag–Sr codoped mesoporous bioactive glass (Ag–Sr‐MBG) was synthesized via a refined Stöber‐type sol–gel method for dual‐function WSL management. FTIR, XRD, XPS, and zeta potential confirmed amorphous structure with successful Ag and Sr incorporation. Ag–Sr‐MBG sustained release of Ca, P, Sr, and Ag ions in artificial saliva. In vitro results showed remineralization capacity with a surface microhardness recovery rate of 74.2% ± 5.7% for Ag–Sr‐MBG, comparable to Sr‐MBG (76.9 ± 4.7%) and higher than Ag‐MBG (59.1% ± 8.2%). Fluorescence microscopy indicated remineralization depths of 90.67 ± 6.84 μm, XRD confirmed hydroxyapatite as the dominant crystalline phase; SEM revealed a smooth enamel surface with uniform mineral coverage consistent with HAp deposition. Concurrently, Ag–Sr‐MBG demonstrated antibacterial efficacy against Streptococcus mutans with a minimum inhibitory concentration of 0.625–1.25 mg/mL. The integration of remineralization and antibacterial functions in a single mesoporous glass phase offers a compliance‐independent approach for WSL management. These findings suggest Ag–Sr‐MBG as a promising bioactive filler for future topical formulations (e.g., varnishes, orthodontic adhesives, or dentifrices) to prevent and manage enamel WSLs by promoting remineralization while suppressing cariogenic biofilms.