Impact of High Sodium Diet on Neovascularization and Osseointegration around Titanium Implant: An in Vivo and in Vitro Study.

Objective: A high sodium (HS) diet is believed to affect bone metabolism processes. Clarifying its impact on osseointegration of titanium (Ti) implants holds significant implications for postoperative dietary management of implanted patients.

Methods: This investigation probed the impact of sodium ions (Na ⁺) on neovascularization and osteogenesis around Ti implants in vivo, utilizing micro-computed tomography, hematoxylin and eosin staining, and immunohistochemical analyses. Concurrently, in vitro experiments assessed the effects of varied Na ⁺ concentrations and exposure durations on human umbilical vein endothelial cells (HUVECs) and MC3T3-E1 cells.

Results: In vivo, increased dietary sodium (0.8%-6.0%) led to a substantial decline in CD34 positive HUVECs and new bone formation around Ti implants, alongside an increase in inflammatory cells. In vitro, an increase in Na ⁺ concentration (140-150 mmol/L) adversely affected the proliferation, angiogenesis, and migration of HUVECs, especially with prolonged exposure. While MC3T3-E1 cells initially exhibited less susceptibility to high Na ⁺ concentrations compared to HUVECs during short-term exposure, prolonged exposure to a HS environment progressively diminished their proliferation, differentiation, and osteogenic capabilities.

Conclusion: These findings suggest that HS diet had a negative effect on the early osseointegration of Ti implants by interfering with the process of postoperative vascularized bone regeneration.