Impact of Aligner Replacement Protocols on Predictability of Planned Dental Movements: Evaluation of Double Aligner

This prospective clinical trial aims to determine whether replacing an aligner after 7 days with a new aligner of a different material affects the predictability of planned dental movements. A total of 114 adult patients undergoing orthodontic treatment with aligners-requiring bilateral tooth movements (extrusion, intrusion, rotation, tipping, or mesiodistal translation)-will be recruited and randomized into three groups with distinct aligner exchange protocols. Group 1: 10 days of exclusive FLX aligner use. Group 2: 7 days of FLX aligner use followed by 3 days of FLX35 use. Group 3: 7 days of FLX aligner use followed by 3 days of a new FLX aligner. Within each group, patients will be further categorized into subgroups based on horizontal, vertical, and rotational movements. Digital study models, radiographs, and standardized clinical photographs will be used to compare planned versus achieved tooth movements. The primary outcome is the predictability of movement, defined as the difference and percentage of planned versus actual movement. Secondary outcomes include participant satisfaction measured via the OHIP-14 questionnaire. Data will be analyzed using descriptive statistics and paired tests appropriate for the split-mouth design. The study is conducted in accordance with the Declaration of Helsinki, and all treatment costs will be covered by the sponsor, NeoDent (JJGC Industria e Comercio de Materiais Dentarios S.A.).