The aim of the study is to detect the changes happed on the surface of the mini-screw regarding bone deposition and ions deposited on the surface after retraction of the canine tooth.
Patient and method: This study was performed over 10 patients, each one received 2 machined titanium mini-screws in the upper arch between the first molar and second premolar for retraction of canine tooth. After retraction of canine the left side was removed (group 1) and the right side was left in place unloaded until treatment finished then removed (group 2) . The two groups were transferred for scanning electron microscopy to analyze the changes happened on the surface regarding bone and ions deposited on the surface.
Results: group 2 samples showed huge differences than group 1 regarding bone deposition on the surface and deposition of calcium and phosphorus ions. Group 2 showed higher bone deposition (3.466 %) than group 1 (0.034%), and in group 2 higher calcium and phosphorous deposition which equal 3.754 , 2.954 mass% respectively than calcium and phosphorus in group 1 which equal 1.949 , 1.606 mass % respectively.
Conclusion: using titanium alloy mini-screws for a long term contact with the bone and body fluids result in alteration on the surface, calcium and phosphorus deposition and randomly organized bony tissue osteointegrated on the surface in spite of smoother surface. This bony tissue formation might be enhanced by extended period of retention of mini-screw inside the alveolar bone.