Nanosized bioceramic dental fillers: Synthesis, structural characterization, and enhanced biocompatibility

Abstract Cu/Zn-doped hydroxyapatite (HA) bioceramics with varying copper (Cu) and zinc (Zn) concentrations were synthesized using a continuous precipitation method at room temperature. The powders were characterized by Rietveld refinement, revealing HA as the primary phase, with an increasing presence of tricalcium phosphate (TTCP) at higher dopant concentrations after thermal treatment. Transmission electron microscopy (TEM) showed particle sizes of 25 ± 5 nm, 35 ± 5 nm, and 45 ± 5 nm for CZH1, CZH3, and CZH5, respectively. High-resolution TEM (HRTEM) confirmed the crystalline structure of HA and identified lattice distortion due to Cu2+ and Zn2+ substitution. Biomineralization was evaluated by immersing the samples in Simulated Body Fluid (SBF) for 14 days; field-emission scanning electron microscopy (FE-SEM) revealed apatite formation on the surface, confirming bioactivity. The incorporation of Cu and Zn is known to confer antibacterial activity and may further enhance HA’s bioactivity, indicating the materials’ potential for future dental applications. GRAPHICAL ABSTRACT HIGHLIGHTS Cu/Zn-doped HA was synthesized using a controlled precipitation method. XRD and Rietveld refinement identified HA and TTCP phases, with variations based on Cu/Zn doping. A bioactive apatite layer formation mechanism was outlined. TEM showed nanoparticle agglomeration and lattice fringes, verifying crystalline HA structure. The findings highlight the potential of Cu/Zn-doped HA/TTCP nanopowders for dental application.