Abstract
Retention is an integral part of orthodontic treatment. Various biomedical agents, methods, and techniques have been introduced over the past 2 decades that could be useful in orthodontic retention. This review focuses on the underlying mechanisms and uses of these biomedical agents, lasers, vibrational therapies, and the most recent types of mechanical retainers. This review is also intended to serve as a resource for orthodontic researchers and clinicians. For researchers, it should facilitate further investigations into the clinical applications of the various agents and methods. For clinicians, it provides an up-to-date summary of new approaches that might be used in the future.
Several biomedical agents, including osteoprotegerin, bisphosphonates, bone morphogenic proteins, and relaxin, were reviewed. The applicability of low-level laser therapy (LLLT) and mechanical vibration also were evaluated, along with the modifications that have been introduced in conventional retention appliances.
Among biomedical agents evaluated in this review, RANKL inhibitor agents, particularly denosumab, hold the greatest potential for future applications in orthodontic retention. In addition, LLLT has been associated with faster periodontal ligament maturation, especially if it is used with conventional retention methods, which might shorten the time required for retention after orthodontic treatment. Mechanical vibration has shown osteogenic effect on bone, even though it failed experimentally to inhibit relapse. Importantly, these new biomedical agents and techniques were mainly investigated experimentally, and further studies are required to confirm or refute their clinical applicability for orthodontic retention.