Recent studies have focused on achieving sound osseointegration applying methods of surface reprocessing of dental implants using ultraviolet (UV) irradiation. However, there have been few reports on the effect of UV irradiation on osseointegration in both the short and long term, and experimental studies using the canine model do not exist. Therefore, the aim of this study was to determine the short- and long-term degree of osseointegration of dental implants according to UV irradiation using a histometric analysis in canine models. Four beagles were used for this study and 24 dental implants were placed. Six implants were inserted with flapless protocols in each mandible. Half of the implants were UV-irradiated prior to implantation. UV-treated and untreated implants were placed one after the other; implant stability was recorded using the implant stability test (IST) immediately after implantation and every seven days thereafter. Two of the beagles were sacrificed after four weeks and the other two after 12 weeks. The implants were removed in block sections and were evaluated histomorphologically and statistically. As a result, we found no statistically significant differences in the mean IST values and in bone-to-implant contact (BIC) in all groups at 4 and 12 weeks.