Immunohistochemical evaluation of bone regeneration induced by human umbilical cord mesenchymal stem cells around implants in an osteoporotic rat model

Background/purpose Osteoporosis in the jawbone can compromise the success of dental implant treatment. Human umbilical cord mesenchymal stem cells (hUCMSCs) have demonstrated osteogenic differentiation potential. This study aimed to evaluate the effect of hUCMSC induction on implant osseointegration in an osteoporotic animal model. Materials and methods Twenty-eight osteoporotic female Wistar rats were divided into control and hUCMSC-induced groups and observed at 2 and 4 weeks. The treatment group received hUCMSC injections into the implant area of the femur osteoporotic model. Specimens were stained using immunohistochemical and haematoxylin and eosin techniques to assess osteogenic marker expression. Data were analysed using Kruskal–Wallis and Mann–Whitney U test. Results Bone-implant volume (BIV) was significantly greater in the hUCMSC-induced groups compared to controls. The expression of osterix, RUNX family transcription factor 2 (RUNX2), tumor necrosis factor (TNF)-α, nuclear factor of activated T cells 1 (NFATc1), collagen type 1, and osteocalcin decreased in osteoblasts from week 2 to week 4. Significant differences ( P < 0.05) were observed between control and hUCMSC groups at both time points. These findings suggest that bone formation was completed by week 4, entering the bone maturation phase, supported by the increased BIV in the hUCMSC group. Conclusion Induction with hUCMSCs promotes both early and late osseointegration in osteoporotic animal models. These results highlight the efficacy of hUCMSCs in enhancing bone healing after implant placement under osteoporotic conditions.