Osteogenesis potential of different graft materials around dental implants: An animal study

Limited research exists concerning the osteogenesis potential of different graft materials. This study compared the osteogenesis potential of autograft, xenograft, and synthetic graft material to support implants inserted in dogs' sternums. Thirteen dogs were divided into three groups based on the sacrifice time (2, 4, and 6 months). Extensive osteotomies were carried out in the sternum bone of dogs, and the implants were placed in the bone defects. The gaps around the implants were then filled with autograft, xenograft (CeraboneŴ), or synthetic graft (Osteone II) materials in all groups of animals. The animals were sacrificed after 2, 4, or 6 months, and bone blocks around the implants were resected. Then, expression of candidate osteogenic genes, including Runt-related transcription factor 2 (RUNX2), alkaline phosphatase (ALP), bone morphogenetic proteins (BMP) 7, and bone gamma-carboxyglutamic acid-containing protein (BGLAP) were assessed by real-time polymerase chain reaction (RT-PCR). The two-way ANOVA manifested no significant interaction between the two factors, "graft materials" and "healing intervals" (P > 0.05). There was no significant difference between the grafting substitutes concerning the expression of ALP, RUNX2, BMP7, and BGLAP (P > 0.05). In addition, no significant difference was observed in the expression of osteogenesis genes between the 2-, 4-, and 6-month groups (P > 0.05). Considering the expression of osteogenesis biomarkers, it appears that xenograft (CeraboneŴ) and synthetic graft (Osteon II) materials can be applied as suitable alternatives to autograft for filling defects around dental implants.