Purpose: To evaluate the effect of ultraviolet-C light (UVC) photofunctionalization treatment time on the biologic activity of airborne particle–abraded and acid-etched (SLA) titanium surfaces and to analyze its physical and chemical mechanisms. Materials and Methods: SLA titanium was treated with UVC light for different lengths of time (10 minutes, 20 minutes, 30 minutes, 1 hour, 2 hours, 4 hours, and 24 hours), and then changes to its surface characteristics were evaluated via electron microscope scanning, X-ray photoelectron spectroscopy (XPS), water contact angle measurement, and zeta potential measurement. The effect of UVC photofunctionalization on the biologic processes of SLA titanium surfaces was assessed by analyzing the bovine serum albumin adsorption, adhesion, proliferation, morphology, and alkaline phosphatase activity of MG-63 cells. Results: UVC irradiation did not change the topography of SLA titanium surfaces. As treatment times increased, the water contact angle decreased from 120 degrees to 0 degrees, and the hydrocarbon content decreased. Zeta potential testing showed increased surface potential of photofunctionalized titanium. In vitro testing showed that cell adhesion, proliferation, morphology, and alkaline phosphate (ALP) activity on titanium surfaces were significantly improved by UVC photofunctionalization. Conclusions: UVC photofunctionalization can improve the biologic activity of SLA titanium surfaces by removing hydrocarbons and increasing the surface potential of titanium.