Surface properties and corrosion behavior of three-dimensional printed titanium mandibular reconstruction plates and commercialized plates

Abstract

Introduction: Three-dimensional (3D) printing technology has been evolving in fabricating patient-specific mandibular reconstruction plates from pure titanium. We have started to use 3D printed titanium plates in mandibular reconstructive surgery. In this pilot experiment, we aimed to examine the difference of surface element compositions and surface roughness of 3D-printed mandibular reconstruction plate, when compared with the commercialized traditional mandibular reconstruction plates. The corrosion behavior of different plates in human serum was also studied and compared. Methods: After virtual surgical planning and computer designing, the 3D printed mandibular reconstruction plates were printed by selective laser melting 3D printer using grade 2 pure titanium. The traditional and 3D-printed titanium mandibular reconstruction plates were cut into standard pieces. Surface topography was detected using the scanning electron microscope (SEM) and atomic force microscope (AFM). Surface element composition was examined using the X-ray photoelectron spectroscopy (XPS). Titanium corrosion in human serum was produced by immersing in human serum for 14 days. Metal released into the human serum was subjected to ion detection using the inductively coupled plasma atomic emission spectroscopy (ICP-AES). Results: Surface roughness was more significant in 3D-printed titanium plates. The surface element composition of 3D-printed titanium plates was almost pure titanium when compared with the titanium oxide film in traditional plates. Titanium ion release in human serum of the traditional and 3D printing groups was 281.78±34.48 (n=3, nM/g) and 140.12±2.50 (n=3, nM/g), respectively. The difference between them was insignificant (p=0.10). Corrosion pits and fissures were detected in both groups after immersion in human serum. Conclusion: Although the 3D-printed titanium mandibular reconstruction plate was endowed with a rough surface of pure titanium, the metal release and surface corrosion were equivalent when compared to the traditional titanium plates. The experimental results should be confirmed in future study with more samples in each group. The 3Dprinted titanium plate seemed favorable as an implant material for mandibular reconstruction.