Local Delivery of Genistein in Peri-Implant Defects Enhances Osseointegration in Ovariectomized Rats

BACKGROUND: Estrogen deficiency, a key factor in osteoporosis, may influence peri-implant healing, which requires cautious and individualized planning for dental implant placement. Functionalizing biomaterials with bioactive molecules, such as soy-derived isoflavone, could enhance their osteoconductive potential. OBJECTIVE: Investigate the performance of genistein in the functionalization of bioactive glass and deproteinized bovine bone by sonochemistry on peri-implant bone repair in ovariectomized rats. METHODS: In total, 50 female rats were divided into five groups (n = 10): blood clot (CLOT); bioactive glass (BG); bioactive glass functionalized with genistein (BG + GEN); deproteinized bovine bone (BO); and deproteinized bovine bone functionalized with genistein (BO + GEN). Thirty days after ovariectomy, implants were placed in the tibia of the rats. Calcein and alizarin were administered at 14 and 24 days post-surgery, respectively. The rats were euthanized 28 days after implant placement for analysis. RESULTS: BO + GEN showed the highest removal torque (5.4 Ncm), significantly higher than BO (2.3 Ncm; p < 0.05), followed by BG + GEN (4.2 Ncm), BG (3.3 Ncm), and CLOT (2.1 Ncm). BG + GEN and BO + GEN upregulated the bone markers (RANKL, OPG, OCN, IBSP) (p < 0.05). Micro-CT revealed higher bone volume percentage (BV/TV) in BO + GEN (11.67%) and BG + GEN (10.51%) versus their controls (p < 0.05). Trabecular separation (Tb.Sp) was significantly reduced in BO + GEN compared to BG (p < 0.05). CONCLUSION: These findings suggest that genistein can potentiate the osteoconductive properties of clinically used biomaterials, enhancing peri-implant bone repair in ovariectomized rats.