Effect of operator experience level on clinical outcomes of indirect- and direct-bonding techniques: a single-center, open-label, quasi-randomized controlled clinical trial

OBJECTIVE: This study aimed to compare the clinical outcomes of indirect‐ and direct‐bonding techniques for bracket placement in orthodontic treatment, focusing on the influence of operator experience. METHODS: A total of 153 patients were quasi‐randomly assigned to the indirect‐ or direct‐bonding group, of whom 124 were analyzed. Clinical outcomes in the two groups were compared and further stratified by operator experience (1‐3 years vs. 4‐6 years). The evaluated parameters included total treatment duration, chair time, discomfort during bonding (visual analogue scale scores), plaque control record, bracket failures, intentional reattachments, and post‐treatment occlusal index (Cast‐Radiograph Evaluation [CR‐Eval] scores). RESULTS: In procedures performed by operators with 1‐3 years of experience, the indirect‐bonding group demonstrated significantly shorter treatment duration, shorter chair time, fewer intentional reattachments, and better post‐treatment occlusal outcomes than the direct‐bonding group. However, the number of bracket failures was significantly higher in the indirect‐bonding group, regardless of operator experience. In procedures performed by operators with 4‐6 years of experience, most parameters showed no significant intergroup differences. CONCLUSIONS: The indirect‐bonding technique improved treatment efficiency and quality, with potential advantages for less‐experienced operators. However, attention to technique is essential to minimize bracket failures. These findings support the incorporation of indirect bonding in clinical training programs.