Surface Micro-Scale Patterning for Biomedical Implant Material of Pure Titanium via High Energy Pulse Laser Peening

Pure titanium (commercial pure cpTi) is an ideal dental implant material without the leeching of toxic alloy elements. Evidence has shown that unsmooth implant surface topologies may contribute to the osteoblast differentiation in human mesenchymal pre-osteoblastic cells, which is helpful to avoid long-term peri-abutment inflammation issues for the dental implant therapy with transcutaneous devices. Studies have been conducted on the grit blasted, acid etched, or uni-directional grooved Ti surface. However, for these existing approaches, the surface quality is difficult to control or may even damage the implant. A novel idea has been studied in which more complex two-dimensional (2D) patterns can be imprinted into the dental implant material of cpTi by high energy pulse laser peening (HEPLP). The strong shock wave generated by HEPLP press a stainless steel grid, used as a stamp, on Ti foils to imprint a 2D pattern. In this study, the multiple grid patterns and grid sizes were applied to test the cell’s favor. The HEPLP induced shock wave pressure profile and history were simulated by a 2D multi-physics hydrodynamic numerical analysis for a better understanding of this technique. Then, the cell culture tests were conducted with the patterned surface to investigate the contribution of these 2D patterns, with the control tests of the other existing implant surface topography forming approaches.