Evaluation of the effects of ultraviolet photofunctionalization on titanium surfaces: in vitro and in vivo study

The aim of this study was to evaluate the effects of UV photofunctionalization on cellular behavior and implant stability using in vitro assays and clinical trial. For that, in vitro tests were performed on smooth titanium disks (machined only) and on disks treated with sandblasted acid-etched (SA) (irradiated or not with UV light for 30 min) to evaluate wettability, roughness, cytotoxicity, cell proliferation, adhesion, and type I collagen production. Subsequently, a clinical study was conducted, in which ten patients were randomly assigned to receive implants that were sandblasted acid-etched and irradiated with UV light (pre-treated for 5 min) on one side, and non-irradiated implants on the contralateral side. Implant stability was assessed biweekly using the Osstell device (ISQ values) up to the 14th week. Here, our data revealed that contact angle analyses showed that (SA) exhibited the highest contact angle among all groups (p < 0.05), whereas UV irradiation significantly decreased it (p < 0.05). The combination of (SA) and UV irradiation exhibited the greatest surface roughness (p < 0.05). Cell viability did not show any significant differences at any time point (p > 0.05), while cell proliferation was significantly increased in the (SA) and UV-irradiated group at 48 h (p < 0.05). Type I collagen levels did not differ statistically among the groups. In the clinical study, UV-irradiated implants demonstrated greater stability at measurement intervals 3, 4, and 6 (p < 0.05). In vitro UV irradiation improved wettability and surface roughness properties without affecting cellular activity. Clinically, the use of UV light resulted in superior implant stability.