Fabrication and physicochemical characterization of zinc- and lithium-modified 58S bioactive glass scaffolds as potential candidates for dental and maxillofacial bone regeneration

Bone defects remain a major clinical challenge in dentistry and oral and maxillofacial surgery. 58S bioactive glasses are promising materials for bone tissue engineering because of their ability to form a hydroxyapatite-like layer and chemically bond to bone tissue. However, tailoring their composition may be necessary to optimize their physicochemical properties and potential biological performance. In this study, 58S bioactive glass scaffolds without dopants (BG0-0) and scaffolds simultaneously containing 5 mol% Li₂O and 5 mol% ZnO (BG5-5) were fabricated by the sol-gel method followed by dip-coating. Their structural, physicochemical, mechanical, and in vitro apatite-forming characteristics were evaluated. X-ray diffraction (XRD) and thermogravimetric/differential thermal analysis (TGA/DTA) were used to investigate the structural and thermal properties of the scaffolds. The scaffolds were immersed in simulated body fluid (SBF) for 7 and 21 days to assess their in vitro apatite-forming ability. Ion release and calcium phosphate deposition after SBF immersion were evaluated using inductively coupled plasma optical emission spectroscopy (ICP-OES) and field-emission scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (FESEM/EDS), respectively. Compressive strength and Brunauer–Emmett–Teller (BET) analyses were performed to evaluate mechanical behavior and porosity-related characteristics. The incorporation of Li⁺ and Zn²⁺modified the XRD diffraction features and crystallization behavior of the 58S glass scaffolds and reduced the crystallization temperature. Although the apatite-formation rate was relatively reduced, the modified scaffolds exhibited a higher specific surface area and porosity, which may support their potential application in non-load-bearing bone tissue engineering. However, the measured compressive strength remained lower than the typical range reported for trabecular bone. Further in vitro cellular, antibacterial, and in vivo studies are required to confirm their biological performance and suitability for bone regeneration applications.