Additive Manufactured Magnetoelectric Wireless Retainer as the Periodontal Remodeler for Post-Orthodontic Tissue Reconstruction and Relapse-Inhibition

Abstract

Modern orthodontics since 1899 has failed to solve rapid and persistent dentition maintenance after tooth movement till now. Traditional post-orthodontic retention using single mechanical fixation cannot actuate periodontal tissue remodel, causing lifelong dependence, huge time costs and discomforts. Current attempts by combining hormone drug with mechanical fixation for improvement are limited by unsatisfactory outcomes and global side effects. Targeting at this 120-year dilemma, a flexible magnetoelectric orthodontic retainer (FMOR) is presented using customized additive manufacturing, serving as periodontal remodeler for high-performance post-orthodontic retention. Wireless magnetoelectric cues display considerable effects in periodontal microenvironment remodel, switching periodontal ligament cell (PDLC) paracrine manner to promote M2 macrophage formation, osteoclastic/osteoblastic balance and collagen metabolism. Using rat and rabbit orthodontic model, application of FMOR is confirmed to significantly strengthen the maintaining of tooth movement outcomes. Mechanistically, magnetoelectric treatment significantly upregulate PDLC genes related to immune response, extracellular matrix organization and osteogenic regulation. This study proposes a non-destructive physical therapeutic strategy for fast activation of periodontal reconstruction after orthodontic treatment and inhibition of tooth relapse for the first time, shedding light on development of next-generation orthodontic retention system for optimized solution of orthodontic relapse.