Effect of local administration of injectable platelet-rich fibrin on root resorption during orthodontic tooth movement in dogs.

Background: This study aimed to assess the effect of local administration of injectable platelet-rich fibrin (i-PRF) on root resorption during orthodontic tooth movement in dogs. Materials and Methods: This animal study was conducted on 4 adult male mongrel dogs. The right and left maxillary first premolars of the dogs were extracted, and a Nickel-Titanium closed coil spring was used to connect the canine to the second premolar with 150 g load. Next, 0.5 cc of i-PRF was injected in one quadrant of the maxilla around the second premolar into the periodontal ligament. The other quadrant of the maxilla served as the control group and received saline injection. Injections were performed at 1, 21, and 42 days, and the dogs were sacrificed after 63 days. Histological sections were prepared and cementum resorption, secondary cementum formation, and number of cementoblasts and cementoclasts were compared between the two groups by the Friedman test, Wilcoxon test, and Mann-Whitney test (α = 0.05). Results: The mean percentage of cementum resorption (17.75% ± 5.56%) and secondary cementum formation (14.50% ± 6.65%), and the mean number of cementoblasts (10.25 ± 2.36) and cementoclasts (9.75 ± 4.71) were insignificantly higher in the i-PRF group than the corresponding values (13.75% ± 4.34%, 8.50% ± 2.88%, 7.75 ± 1.25, and 6.50 ± 3.10, respectively) in the control group ( Conclusion: Administration of i-PRF insignificantly increased the percentage of cementum resorption, secondary cementum formation, number of cementoblasts, and number of cementoclasts.