A single-operator, single-center randomized controlled trial (RCT) with a 1:1 allocation ratio will be conducted for patients seeking orthodontic treatment with fixed appliances. The study will take place at the Postgraduate Orthodontic Clinic, College of Dentistry, University of Baghdad, Baghdad, Iraq. Patients who meet the eligibility criteria will be randomly assigned to one of two bracket-type groups. To eliminate inter-operator variability, all patients will be treated by a single operator.
A standardized protocol will be followed. Each patient will undergo extraoral and intraoral photography, intraoral scanning with Medit i700 (Medit Corp., Seoul, South Korea), and radiographic evaluation (CBCT and lateral cephalogram). On bonding day, gingival index and plaque index will be assessed. All teeth will then be isolated and cleaned with a mixture of water and pumice using a rubber-polishing cup on a low-speed handpiece. The teeth will be rinsed and dried with an oil-free air syringe, and etched using the conventional acid-etching technique (37% orthophosphoric acid applied for 30 seconds). The surfaces will be thoroughly rinsed with water for 10 seconds to ensure complete removal of the etchant, in accordance with the manufacturer's instructions. The enamel will then be gently dried with air until a frosty-white appearance is observed.
A uniform coat of universal bonding primer (Ortho Solo, Ormco Corp., Glendora, California, USA) will be applied to the etched surfaces using a nylon bond brush. Each tooth will receive a gentle air blow for 2 seconds with the air stream directed perpendicular to the enamel surface. After etching and priming, a thin layer of adhesive (Green Glow, Ormco Corp., Glendora, California, USA) will be applied to the mesh base of each bracket, which will be positioned on the buccal surface of the tooth using a bracket holder. The bracket height will be determined according to the manufacturer's instructions. Any excess adhesive will be carefully removed from around the base of the bracket with a dental probe prior to curing, without disturbing the seated bracket. The adhesive will then be light-cured for 20 seconds.
In the intervention group, Damon Ultima brackets (Ormco Corp., Glendora, California, USA) will be bonded from the second molar to the second molar in each arch. In the comparison group, MBT Mini Diamond brackets (Ormco Corp., Glendora, California, USA) will be bonded from the second molar to the second molar in each arch. Damon Ultima archwires (Ormco Corp., Glendora, California, USA) will be used for both groups in the following sequence: 0.014-inch CuNiTi, 0.018-inch CuNiTi, and 0.014 × 0.0275-inch CuNiTi.
All patients will receive an oral hygiene kit, a brochure on dietary recommendations, and a printed questionnaire to assess pain during treatment (developed for the study). Patients will be reviewed every 8 weeks, during which gingival index, plaque index, photographs, intraoral scans, and questionnaires will be collected. Patients will also be instructed to contact the operator immediately and attend as soon as possible in the event of bracket bond failure. The treatment will be followed up for 6 months.
