Alveolar ridge bone augmentation using gene-activated bone substitute: long-term clinical follow-up

Objective: to evaluate the long-term clinical results of the gene-activated bone substitute based on octacalcium phosphate and plasmid DNA encoding vascular endothelial growth factor in bone grafting for dental implantation. Materials and methods. This clinical study analyzed the long-term treatment results of 100 patients with alveolar ridge atrophy and acquired bone defects of the jaws who underwent bone grafting with gene-activated bone substitute, starting with registration clinical trials initiated in 2017. All patients enrolled in the study underwent bone grafting of the upper or lower jaws using the gene-activated bone substitute in standard surgeries (sinus lifting, guided bone augmentation, cystectomy, etc.). The results of delayed clinical observation were assessed at different time points from 6 months to 7 years after bone grafting using clinical methods and computed tomography (CT), as well as histological analysis of trephine biopsy specimens. Results. Newly formed tissues of bone density were detected in the bone grafting area in all patients within 6 months after surgery. The density remained at a high level during 7 years of follow-up. The volume of the newly formed tissues was maintained with minimal resorption: the decrease in volume was 12±5.9%. Histologically, newly-formed bone tissue with partially resorbed bone substitute fragments were indentified in trephine biopsy specimens. Conclusion. Thus, the gene-activated bone substitute has proven its safety and long-term effectiveness in jaw bone grafting for up to 7 years, and it can be used to treat patients requiring dental implantation.