Synthesis and in Vitro Assessment of Bioglass and Hydroxyapatite Nanocomposites for Biomimetic Dentin Remineralization

Abstract

Introduction: The management of dentin demineralization, commonly associated with caries, erosion, and hypersensitivity, continues to be a critical challenge in restorative dentistry. Conventional restorative materials often restore only structural integrity, failing to achieve true biological repair. Bioactive glass (BAG) and hydroxyapatite (HAP), both recognized for their excellent biocompatibility and bioactivity, have emerged as promising alternatives for biomimetic remineralization. BAG, through controlled ion release, stimulates apatite formation, while HAP, being chemically analogous to dental mineral, directly supports mineral deposition.

Objectives: This study aims to synthesize and characterize BAG/HAP nanocomposites, evaluate their surface morphology and functional group incorporation, and assess their hemocompatibility to determine suitability for dentin remineralization applications.

Methods: BAG was synthesized using the sol-gel method, while HAP was produced through precipitation involving calcium nitrate, orthophosphoric acid, and ammonia. Both were sintered at 600°C. The composites were subjected to Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and hemolysis assay.

Results: Haemolysis testing revealed 2% lysis, indicating excellent hemocompatibility. FTIR spectra confirmed functional groups essential for bioactivity, including phosphate, carbonate, hydroxyl, and silica vibrations. SEM analysis demonstrated a porous, nanostructured surface with high surface area, which is favorable for nucleation and ion exchange during remineralization.

Conclusions: The synthesized BAG/HAP nanocomposites displayed desirable structural, chemical, and biological properties for dentin remineralization. Their biomimetic potential supports their future role in restorative dentistry as capping agents, fillers, and bioactive restorative materials. Further long-term in vivo studies and mechanical evaluations are necessary to establish clinical applicability.