Thesis (M.Sc.) - Cairo University - Faculty of Oral and Dental Medicine - Department of Orthodontics

This experimental study was carried out to compare the behavior of ball bearing brackets with the unmodified brackets not containing ball bearing regarding the friction between the bracket and the orthodontic wire. The samples consisted of 60 brackets 10 unmodified four wing brackets 10 modified four wing brackets. 10 unmodified Six wing brackets.10 modified Six wing brackets.10 unmodified passive self - ligating brackets. 10 modified passive self - ligating brackets. The details of bracket modification are still patent pending. The brackets were tested with 0.019 X 0.025 inch and 0.016 x 0.022 inch straight stainless steel wire. Static friction was measured. With the 0.019 x 0.025 inch Stainless Steel wire, the modified Four wing brackets showed higher static friction than the unmodified brackets. The modified Six wing brackets showed less static friction than the unmodified ones. The modified self ligating brackets showed higher static friction than the unmodified brackets. With the 0.016 x 0.022 inch stainless steel Wire, The modified Four wing brackets showed less static friction than the unmodified brackets. The modified Six wing brackets showed higher static friction than the unmodified brackets. The modified Self ligating brackets showed higher static friction than the unmodified ones

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