Multifunctional Lithium–Calcium–Silicon Bioceramic Resin Composite for Enhanced Dental Remineralization and Reparative Dentin Formation

Deep carious lesions can progressively demineralize dentin and approach the pulp chamber, risking pulp exposure. Indirect pulp capping seeks to preserve remaining dentin and induce reparative dentin formation to protect the pulp and avoid root canal therapy. However, conventional pulp-capping materials often lack sustained remineralization and sufficient dentinogenic induction. In this study, lithium calcium silicate (Li2Ca4Si4O13) resin composite (RC) is designed to enhance dentin remineralization, stimulate reparative dentinogenesis, and provide anti-inflammatory activity. In oral conditions, the RC steadily released lithium, calcium, and silicon ions. In vitro, the extract of RC increases alkaline phosphatase activity, promotes mineral nodule formation, and upregulates odontogenic genes (DSPP, DMP1, MEPE) in dental pulp stem cells, while reducing the expression of Il-1β, Tnf-α, and Il-4 of neutrophils. Demineralized dentin treated with the RC shows remineralization after 21 days in rat oral environment. Rat dentin exposure model shows that indirect pulp capping with RC generates more robust reparative dentin formation than iRoot BP. These findings demonstrate that the RC is a novel bioactive material combining effective remineralization, dentinogenic, and immunomodulatory properties, with strong potential for advanced dental remineralization and indirect pulp-capping therapies.