Introduction: Fixed orthodontic appliances usually provide a shelter for plaque and stain deposition on teeth, stimulating patients to seek teeth bleaching before finishing their orthodontic treatment course. The influence of the whitening agents on the bonded brackets has not been investigated yet.
Aim of the study: The current study was conducted to investigate the effect of bleaching techniques on surface roughness of three different types of esthetic orthodontic brackets.
Materials and methods: Forty five healthy premolars were selected and classified into 3 groups according to the technique of bleaching. Group A was the control un-bleached group, while groups B and C were either subjected to “in-office" or “at-home" bleaching, respectively. For each group, 3 types of brackets were tested; Transcend ® (polycrystalline ceramic), Inspire Ice® (Monocrystalline ceramic) and Spirit ® (Resin bracket). Brackets were bonded and bleached according to manufacturers' instructions and surface roughness was evaluated using environmental scanning electron microscope (ESEM). For statistical analysis, ANOVA and LSD tests were used.
Results: Brackets subjected to at-home bleaching showed lower Ra values than those subjected to in-office bleaching. Ice ® brackets showed the lowest Ra values, in comparison to the other tested types of brackets.
Conclusion: At- home bleaching had lower roughening effect on orthodontic brackets, as compared to in-office technique. Ice brackets were most resistant to the roughening effect of the investigated bleaching agents.