Effect of Blue-light-emitting Diode Exposure on Osteoprotegerin Level During Orthodontic Relapse in Rats

Introduction: The post-orthodontic stabilization is a very important phase because teeth alignment tends to relapse. Osteoprotegerin (OPG) is a glycoprotein produced by osteoblasts and inhibits osteoclastogenesis, which reduces bone resorption. Blue−light emitting diode (LED) provides a photobiomodulation effect, thereby increasing adenosine triphosphate production. This study aimed to determine the effect of blue−LED exposure on the OPG on the pressure sides level in gingival crevicular fluid (GCF) during the relapse phase. Methods: Ten Wistar rats were divided into 2 groups (n = 10), control groups and blue−LED groups. An open coil spring was used to apply a 35-gram orthodontic force to the mandibular inter-incisor reciprocally. After seven days, the open coil was maintained without activation as retention by a GIC stopper. Blue-LED was exposed for 30 seconds in the stabilization phase for 7 days. GCF was obtained during the relapse phase on days 0, 3, 7, and 14. ELISA test was used to analyze the OPG level. The ANOVA and Post Hoc LSD tests were used to evaluate the data. Results: OPG levels in the blue−LED group were higher than in the control group. OPG levels in the blue−LED group have increased significantly, starting on days 3, 7, and 14, during the relapse phase (p <0.05). Conclusion: Blue−LED exposure intensity of 1000 mW/cm2 and a wavelength of 490 nm increased the level of OPG in GCF on the pressure sides during orthodontic relapse in rats. © 2023 UPM Press. All rights reserved.