Biological Effect of Titanium's Surface Roughness on Periodontal Ligament Cells

This paper aims to evaluate the effect of surface roughness of commercially pure titanium (Ti) on the adhesion and proliferation of human periodontal ligament cells (hPDLCs). Four Ti surfaces of dental implants were compared through different systems in vitro. The surface roughness of Ti was measured by TR240 mobile surface roughmeter. hPDLCs were seeded on Ti and their response to smooth and rough surfaces manufactured from Ti was examined by cell morphology, acridine orange fluorescent staining and alkaline phosphatase (ALP) activity. The surface roughness data of the samples for Group A to D was 0.5995plusmn 0.0083, 0.4065 plusmn 0.0046, 0.3588 plusmn 0.0118 and 0.0087 plusmn 0.0022 mum respectively (F = 6190, P < 0.0001). There was significant difference in surface roughness between all the groups (P < 0.001). hPDLCs were fusiform in shape after they were seeded on Ti, simultaneously few hPDLCs were triangle or polygon in shape. hPDLCs exhibit decreased proliferation on rougher surfaces based on reduced cell amount through the fluorescent staining. hPDLCs had decreased ALP mRNA expression when grown on rougher surfaces. Surface roughness of titanium is one of the important parameters that affect hPDLCs behavior.