Amir Hossein Mirhashemi

, Atefe Saffar Shahroudi, Keyvan Shahpoorzadeh, Niloofar Habibi Khameneh
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Abstract
Background: This study was designed to compare the force decay pattern of two different orthodontic active tiebacks which were exposed to five different commercially available mouth rinses. Methods: In this in vitro study ninety transparent active tiebacks (ATB) and ninety gray ATB were divided into 6 groups. One was the control group and the others were exposed to one of these mouth rinses twice a day for 60 seconds: Listerine, chlorhexidine, Orthokin, Persica and fluoride. The initial force of ATB was 250 gr at 24 mm extension. The force of active tiebacks was measured on the 1, 7, 14 and 28 following days by a digital gauge. Results: The highest percentage of force loss was observed between the days of 14 and 28 (p<0.05). At the end of the study, persica group had the highest amount of force degradation among both types of ATB. In transparent group it was followed by Orthokin, Listerine, fluoride, chlorhexidine and control respectively. While, in the gray group, Orthokin, chlorhexidine, control, Listerine and fluoride came orderly. In some groups the differences between transparent and gray ATB was significant. In the control group, the force of transparent ATB was significantly greater than gray ones on 7th and 14th day but not significantly after 4 weeks. Conclusion: Active tiebacks force degradation could be exacerbated by use of some mouth rinses. There were some differences between force relaxation pattern of transparent and gray ATB, of which the knowledge could be beneficial in choosing appropriate O-rings for making ATBs.
Keywords: Active tiebacks, Force decay, Mouth rinse, Orthodontics