Response of Dental Enamel to Office External Bleaching Following Fixed Orthodontic Treatment using Two Types of Orthodontic Adhesives (Clinical Prospective Study)

ABSTRSCT The aims of this study is to evaluate the response of enamel surface either (bonded or unbonded) to external bleaching following the debonding of fixed orthodontic therapy using two types of adhesive systems. Methods 48 subjects, 16 are non orthodontic individuals (control), and the 32 individuals are candidate to fixed orthodontic therapy (experimental), 16 individuals of the experimental group were bonded by enlight (composite) while the other 16 individuals were bonded by GC FuJi ortho (GIC), all groups were subjected to external bleaching, color measurement has been done in term of (L, a and b) before and after the bleaching process. To get color difference E which represents the enamel response to external bleaching. T test was used to exclude the gender differences, while ANOVA one way test has been used to detect the color difference in E among control group, enlight composite and GC Fuji ortho, again ANOVA one way used to detect the region difference of the E among incisal, middle and gingival third in all groups. Result there is no significant difference in E between the genders. ANOVA one way shows no significant difference (pless than0.5) in E among the groups (control, enlight composite and GC Fuji ortho). Regarding the labial thirds the ANOVA one way shows no significant difference in E among the three thirds in (control and GC Fuji ortho) adhesive, while in composite group the value of E in middle thirds is reduced significantly (pless than0.05) in comparison with incisal and gingival thirds. Conclusion enamel response to external bleaching is not affected by the bonding whether enlight composite or GC Fuji ortho. The enlight composite group shows significant reduction in response of middle thirds in comparison with the gingival and incisal thirds.