Inclusion Criteria:  Young healthy subjects undergoing orthodontic treatment. Patients with all permanent teeth present without any oral pathology. Healthy gingiva with no bleeding on probing before start of orthodontic treatment and a normal pocket depth (1-3mm) on all teeth. No WSLs (score = 1  Exclusion Criteria:  History of smoking, patients suffering from any systemic illness like diabetes. Gingivitis or an active periodontal disease. Carious lesions on labial/buccal surface of teeth. Mentally handicapped individuals