Improving osteogenic properties of zirconia ceramic via glow discharge plasma-enhanced deposition of amine organic compound

Background/purpose: Osseointegration potential is greatly depended on the interaction between bone cells and dental implant surface. Since zirconia ceramic has a bioinert surface, functionalization of the surface with an organic compound allylamine was conducted to overcome its drawback of minimal interaction with the surrounding bone. Materials and methods: The zirconia surface was initially treated with argon glow discharge plasma (GDP), then combined with amine plasma at three different conditions of 50-W, 75-W and 85-W, to prepare the final samples. The surface characteristics and cell biocompatibility were then evaluated. Results: Surface morphology analysis revealed a bulbous pattern on allylamine-treated sample groups. The aromatic C–H, C–O, N–H, C ˆ C, and C–H stretching and functional groups have been identified. Surface roughness increased, and hydrophilicity improved after surface modification. Cell viability analysis showed the highest result for the allylamine 50-W (A50) group. Alkaline phosphatase (ALP) assay indicated the A50 group had the highest activity, subsequently promoting late-stage mineralization at day 21. The reverse transcription-quantitative polymerase chain reaction (RT-qPCR) data demonstrated a significant upregulation of osteogenic gene expressions from day 1 to day 21. Conclusion: The allylamine-treated surface demonstrates immense enhancement in the surface hydrophilicity as well as in the viability, differentiation, and osteogenic properties of osteoblast-like cells. This makes it a promising candidate for future dental implant applications.