Comparing initial wound healing and osteogenesis of porous tantalum trabecular metal and titanium alloy materials.

Porous tantalum trabecular metal (PTTM) has long been used in orthopedics to enhance neovascularization, wound healing, and osteogenesis; recently it has been incorporated into titanium alloy dental implants. However, little is known about the biological responses to PTTM in the human oral cavity. We hypothesized that, compared to conventional titanium alloy; PTTM had greater expression of genes specific to neovascularization, wound healing, and osteogenesis during the initial healing period. Twelve subjects required at least four implants in the mandible were enrolled. Four 3mmx5mm devices, including 2 titanium alloy tapered screws and 2 PTTM cylinders, were placed in the edentulous mandibular areas using a split-mouth design. One device in each group was trephined for analysis at 2 and 4 weeks after placement. RNA microarray analysis and ingenuity pathway analysis were used to analyze osteogenesis gene expression and relevant signaling pathways. Compared to titanium alloy, PTTM samples exhibited significantly higher expressions of genes specific to cell neovascularization, wound healing, and osteogenesis. Several genes including bone morphogenic proteins, collagens, and growth factors were upregulated in the PTTM group compared to the titanium alloy control. PTTM materials may enhance the initial healing of dental implants by modifying gene expression profiles.