Kevser Sökmen, Serkan Dündar, Erhan Cahit Ozcan, Murat Tanrısever, Ozmen Istek, Umit Koray Can
Background and Objectives: The aim of this study was to investigate the effects of local melatonin application on osseointegration of machined (MAC), resorbable blast material (RBM), and sandblasted and acid-etched (SLA) surface implants placed in rat tibiae, utilizing the reverse torque analysis. Materials and Methods: A total of 72 female Sprague-Dawley rats, weighing between 270 and 300 g, were included in the study. The rats were divided into six groups, and samples in which the implants were not properly placed were excluded from the study: control groups consisting of MAC-CNT (n = 12), RBM-CNT (n = 11), and SLA-CNT (n = 12), and local melatonin (MLT)-treated groups consisting of MAC-MLT (n = 12), RBM-MLT (n = 10), and SLA-MLT (n = 10). The implants were surgically placed into the tibiae of the rats under general anesthesia. Following a four-week experimental period, the biomechanical bone-implant connection level was evaluated using reverse torque analysis. Results: The lowest mean biomechanical bone-implant connection value was observed in the MAC-CNT group, whereas the highest value was recorded in the SLA-MLT group. Compared with the MAC-CNT group, all other groups demonstrated statistically significantly higher biomechanical connection values (p < 0.05). The SLA-MLT group showed significantly higher osseointegration levels than both the MAC-MLT and RBM-MLT groups (p < 0.05). In contrast, no significant difference was detected between the MAC-MLT and RBM-MLT groups (p > 0.05). Both MAC-MLT and SLA-MLT groups exhibited statistically significantly higher biomechanical bone-implant connection values compared to control groups (p < 0.05). Conclusions: Local melatonin application positively affected osseointegration in SLA and MAC surfaced implants. In contrast, local melatonin application did not provide any additional contribution to osseointegration in RBM surfaced implants.