Root resorption and RANKL concentration in orthodontic tooth movement accompanied by topical PGE2 gel application

The current study sought to determine root resorption and the correlation between root resorption and Receptor Activator Nuclear ß Ligand concentration, following orthodontic force accompanied by the application of PGE2 gel.The subjects were 7 male Macaca fascicularis. The maxillary right canine was the experimental tooth while the maxillary left canine served as the control. The gel was applied at 0, 2nd and 4th hours, on a weekly basis for 3 weeks. Root resorption was determined by osteoclast count using histological staining with TRAP. A light microscope with 200x enhancement was used. The RANKL concentration in gingival crevicular fluid was measured using ELISA. Root resorption and RANKL concentration were greater in theexperimental tooth than in the control tooth, but the difference was not statistically significant (p>0.05). The correlation between root resorption and RANKL concentration was weak. Root resorption always occurred in both the experimental and the control tooth. PGE2 gel application did not make root resorption worse.