A comparative evaluation of osteoprotegerin and receptor activator of nuclear kappa B ligand in gingival crevicular fluid during canine retraction with elastomeric chain and nickel titanium coil spring: Anin vivostudy

Abstract

Objective: The objective of this study is to evaluate and compare the level of receptor activator of nuclear kappa B ligand (RANKL) and osteoprotegerin (OPG) in gingival crevicular fluid (GCF) during canine retraction with nickel-titanium (NiTi) coil spring and elastomeric chain. Materials and Methods: Ten patients between the ages of 13–17 years requiring canine distalization after first premolar extraction were selected. NiTi coil spring was placed on one side and elastomeric chain on the contralateral side. GCF sampling was done at baseline, 1 h, 24 h, 168 h, 1 month from the distal site of the test teeth after the application of compressive force. RANKL and OPG concentration were detected by enzyme-linked immunosorbent assay. Results: In the NiTi coil spring side, the RANKL levels in GCF increased and OPG levels decreased in a time-dependent manner. Increase in RANKL and decrease in OPG were significant when compared with the baseline. In the elastomeric chain side, the RANKL levels were significantly higher and the OPG levels significantly lower at 24 h, the RANKL levels showed a significant decrease and OPG levels showed a significant increase from 24 h to 1 month time intervals. The RANKL and OPG levels in GCF when compared individually to the NiTi coil spring and elastomeric chain showed a significant difference at 24 h, 168 h, and 1 month after initiation of compressive force. Conclusion: The result suggests that RANKL and OPG expression during orthodontic tooth movement varies at different time intervals and according to the type of force delivery system.