Abstract
Objective: This study examines the effect of ultraviolet C (UVC) irradiation on the wettability and the potential bacterial surface contamination of expired dental implants. Materials and Methods: Twenty expired titanium implants in intact packaging were tested. The examined implants were exposed to UVC light of 254 nm wavelength and 8-watts power at two intervals for 15 minutes each. Bacterial culture was performed for all implants in three events; immediately after unpacking, after experimental contamination with freshly collected saliva, and after the first UVC exposure. As an indicator of surface wettability, Static-contact angle (S-CA) measurement was done for all implants three times; Pre-radiation and after the first and second UVC exposures. Results: All tested implants showed hydrophobic surface characters before exposure to UVC, and superhydrophilic surfaces were obtained following the second UVC exposure. All sealed expired implants didn't show any bacterial growth, and all saliva contaminated implants showed no bacterial growth after the first UVC exposure. There was no statistical correlation between implants' aging periods and the expired implant statistic contact angles. Conclusion: The used UVC source showed the ability to restore the expired implants to a superhydrophilic status and eliminate the bacterial contamination on the implant surfaces. Intact packaging protects outdated implants from bacterial contamination.