How often should clear aligners be changed? A review of current literature

Clear aligners are becoming increasingly popular, especially among adults. Aligner companies typically recommend changing aligners weekly to improve treatment efficiency and shorten treatment time. However, there are currently a limited number of high-quality clinical studies addressing this topic. To investigate this further, a comprehensive search was conducted using electronic databases, including Medline, PubMed, Web of Science, and Scopus, for studies comparing different change intervals. Of 1,104 records screened, 15 studies met the criteria. Most compared 7-day with 14-day wear. Some studies showed slightly better accuracy with 14-day changes for selected movements but usually below clinical thresholds, while others found no significant differences in accuracy or overall treatment quality. In extraction cases, overall outcomes were similar across 7-, 10-, and 14-day protocols. Overall, weekly change protocol appears acceptable for simpler movements and early evidence suggests that it may be feasible and promising even in extraction cases, but more high-quality data are needed.