The aim of this study is to compare the clinical efficacy of different residual orthodontic adhesive removing methods for rebonding debonded metal attachments.

1. To evaluate and compare the bond failure rates of rebonded brackets using two methods to remove the adhesive remnant and comparing them with contralateral teeth.
2. To evaluate and compare the bond failure rates of rebonded brackets between different quadrants and arches.
3. To evaluate and compare the bond failure rates of rebonded molar tubes using two methods to remove the adhesive remnant and comparing them with contralateral teeth.
4. To evaluate and compare the bond failure rates of rebonded molar tubes between different quadrants and arches.

Inclusion Criteria:

1. Patients need metal fixed orthodontic appliance treatment;
2. Complete set of permanent dentition with fully erupted teeth on both arches;
3. Intact teeth and mainly their buccal surfaces are free from caries, fillings, or gingival hyperplasia;
4. No occlusal interferences that can affect the ideal position of attachments, especially in the lower arch.

Exclusion Criteria:

1. patients have crown, missing teeth, or craniofacial anomalies.
2. patients have congenital enamel defects specially their buccal surface.

The attachments will carry out by main investigator who give each side coded key then the attachments will be rebond by blind specialist. The participants will be blinded to group assignment and interventions (double-blinded trial).