Validation of a roughness parameters for defining surface roughness of prosthetic polyethylene Pe-Lite liner

Abstract

The Biosculptor's CNC milling machine, the Biomill, offered four different surfaces machined on positive models. This study aims to adopt the surface topography method in characterizing the four different surface roughness of polyethylene Pe-Lite liner as a product of the Biomill. Three surface parameters chosen were the arithmetic average (Ra), root mean square roughness (Rq), and ten-point height (Rz). The surface parameters were used to define the four different surfaces (STANDARD, FINE, COARSE, and FAST) and then compared with the same liner material from a conventionally fabricated socket. The Ra values of the conventional liner, 8.43 μm, were determined to be in-between the Ra values of STANDARD and FAST surfaces which were 8.33 μm and 8.58 μm respectively. STANDARD surface required 43.2 min to be carved while FAST surface took almost only a third of the time compared to STANDARD surface (conventional socket takes 2–3 days). The results of this study would be one of the guidelines to the prosthetists using the Biosculptor in socket fabrication to produce sockets according to the suitable surface to cater to different requirements and levels of activity of each amputee.