Effect of porous titanium coating thickness on in vitro osteoblast phenotype expression

Abstract

Aim: This study aimed at determining the effect of different thickness of porous titanium (Ti) coating, 0.5, 1.0 and 1.5 mm thick (PC-0.5, PC-1.0 and PC-1.5), on osteoblast phenotype expression. Materials and methods: Dense Ti discs coated with 0.5, 1.0 and 1.5 mm of porous Ti (PC-0.5, PC-1.0 and PC-1.5, respectively) were fabricated by powder metallurgy process with pore size typically between 50 and 400 μm and porosity of 60%. Osteoblastic cells obtained from human alveolar bone were cultured on dense Ti (D-Ti) and PC-Ti discs for periods of up to 17 days. Results: Cultures grown on PC-Ti exhibited higher cell proliferation rate than on D-Ti. By comparing PC-Ti groups, it was observed statistical differences on culture grown only at day 10 (PC-0.5<PC-1.0 and PC-1.5). Cells cultured on PC-1.5 presented the highest gene expression of type I collagen (COL), alkaline phosphatase (ALP), and osteocalcin (OC). The calcium content was significantly greater on PC-1.5 compared to all other groups. Conclusion: These results indicate that PC-Ti favored osteoblastic cell proliferation. In addition, they increased gene expression of osteoblastic markers and higher content of mineralized matrix was observed on the thicker PC-Ti coating (PC-1.5). Therefore, further in vivo evaluations should be done in order to investigate whether this structure should be considered for clinical implant applications.

Keywords

• Bone
• Cell culture
• Cell-material interactions
• Porous coated
• Titanium