Effect of local injection of injectable platelet‑rich fibrin on bone remodeling during orthodontic tooth movement in dogs

This study aimed to assess the effect of local injection of injectable platelet‑rich fibrin (i‑PRF) on bone remodeling during orthodontic tooth movement in dogs.

In this animal study, the maxillary first premolars of four adult male mixed‑breed dogs were bilaterally extracted, and a nickel–titanium closed coil spring with 150 g force was placed between the canine and second premolar teeth. One quadrant of the maxilla was randomly selected as the test quadrant, and 0.5 cc i‑PRF was injected into the periodontal ligament (PDL) around the second premolar at 1, 21, and 42 days.The other quadrant served as the control group and received saline injections.The dogs were sacrificed after 63 days,histological sections were prepared,and changesin bone remodeling were assessed by comparing the percentage of osteogenesis and number of osteoblasts and osteoclasts between the two groups by theWilcoxon and Mann–Whitney U‑tests (α = 0.05).

The percentage of osteogenesis (16.0% ± 4.96% in i‑PRF and 13.5% ± 4.43% in the control), the percentage of newly formed lamellar bone (10.25% ± 2.87% in i‑PRF and 8.75% ± 2.36% in the control),the percentage of woven bone (5.75% ± 2.21% in i‑PRF and 4.75% ± 2.36% in the control), the number of osteoblasts (15.0 ± 3.46 in i‑PRF and 11.75 ± 2.36 in the control), and the number of osteoclasts (11.25 ± 4.34 in i‑PRF and 6.25 ± 2.62 in the control) were not significantly different between the two groups (P > 0.05).

PDL injection of i‑PRF around the second premolars of dogs under orthodontic force had no significant effect on bone remodeling.