Development of an experimental pulp capping material containing antibacterial and remineralizing peptide: an in vitro study

This study aimed to characterize an experimental pulp-capping material prepared by incorporating a hydroxyapatite-binding antimicrobial peptide (HBAMP) into a resin-modified calcium silicate–based material (RMCS), and to evaluate its antibacterial, mineral deposition potential, and cytotoxicity properties. The experimental groups were defined as Control, 1% HBAMP-RMCS, and 3% HBAMP-RMCS. Standard polymerized RMCS discs were fabricated for XRD, degree of conversion, microhardness, antibacterial, and cytotoxicity assays. For dentin surface analyses, human mandibular third molars were used. Half of the dentin surfaces were treated with the pulp-capping material, followed by application of a universal adhesive and a nanohybrid composite resin. After 72 h of storage in distilled water, and microhardness and SEM–EDX analyses were performed. Data were statistically analyzed. The incorporation of HBAMP at 1 wt% and 3 wt% into RMCS caused no significant changes in the degree of conversion or microhardness values ( p > 0.05). Regarding mineral deposition potential, HBAMP incorporation resulted in numerical increases in dentin microhardness and Ca/P ratio, although these changes were not statistically significant among the groups ( p > 0.05). While HBAMP exhibited potent antibacterial activity against S. mutans and L. casei strains, no inhibition zones were formed when it was incorporated into the RMCS. Furthermore, no statistically significant differences were detected between the mean cell viability of the experimental groups in the MTT assay at the 24-h and 48-h evaluations( p > 0.05). The incorporation of HBAMP enhanced the early mineral deposition on dentin surfaces of RMCS without adversely affecting its physical properties. The 1% HBAMP-RMCS group demonstrated more consistent outcomes with respect to mineral deposition and cytotoxicity. The antibacterial effect of HBAMP was attenuated when incorporated into RMCS.