Effect of Locally injected PRP on RANKL and OPG in gingival fluid during orthodontic tooth movement: A Canine Model Study

Blood platelet-rich plasma (PRP) contains a variety of biologically active components, including growth factors. The objective of this study was to examine the effects of topical PRP injection on osteoprotegerin (OPG) and receptor activator of nuclear factor kappa-B ligand (RANKL) mediator levels in the gingival groove fluid of dogs with orthodontic treatment. In this study, six adult male dogs, 10-12 months of age, were included. Every dog was randomly assigned to either an experimental or a control group by injecting thrombin-CaCl2 and PRP into one side (experimental group) and thrombin-CaCl2 and a placebo into the opposite side (control group). During the experiment, a maxillary quadrant on one side was assigned as the experimental group and the opposing side as the control group. Maxillary first premolars were bilaterally extracted, followed by the placement of a titanium nickel spring (200 grams) between the second premolar and the canine. A mixture of PRP and CaCl2-thrombin was administered to the experimental group on days 1, 21, and 42, whereas the control group received CaCl2-thrombin mixed with a placebo. Samples of gingival groove fluid were collected regularly during the study (on days 0, 1, 2, 7, 21, 42, and 63). A RANKL and OPG enzyme-linked immunosorbent assay was performed to measure the levels of the mediators. The experimental group exhibited consistently higher OPG levels (p<0.001), indicating that the topical injection of PRP had a notable effect on OPG levels and the associated regulatory mechanisms involved in bone remodeling. The RANKL mediator levels in the gingival fluid of orthodontic-treated teeth were increased over time in the experimental group, while the control group did not show any significant changes over time. The topical injection of PRP demonstrated a significant influence on OPG and RANKL mediator levels, reaffirming its potential as a therapeutic approach for optimizing bone remodeling and enhancing treatment outcomes. • PRP injection significantly increased OPG levels during orthodontic tooth movement. • RANKL levels rose over time in the PRP-treated group but not in controls. • Local PRP application influenced bone remodeling mediators in gingival fluid. • PRP shows therapeutic potential to optimize orthodontic treatment outcomes.