Repeated Injections of i-PRF for Decreasing Root Resorption After the Orthodontic Treatment.

Effect of the Injectable Platelet-rich Fibrin on the Orthodontically Induced Apical Root Resorption Following Non-extraction-based Orthodontic Treatment in Adults: A Randomized Controlled Clinical Trial.

Mandibular incisor crowding is a frequent issue that prompts many adults to seek orthodontic treatment. The treatment may enhance patients' quality of life, facilitate dental plaque control, and improve the quality of periodontal tissue. However, this treatment is accompanied by several side effects, including resorption of the apical portion of the teeth. Platelet-rich concentrates, such as injectable platelet-rich fibrin, have been shown to have positive effects on both soft- and hard-tissue healing. They may serve as a beneficial self-derived material to prevent this complication.

In recent years, increasing attention has been directed toward biologically driven approaches to modulate tissue responses during orthodontic treatment and minimize adverse effects, such as root resorption. Platelet-rich fibrin (PRF), a second-generation autologous platelet concentrate, has emerged as a promising biomaterial due to its high concentration of platelets, leukocytes, and a fibrin matrix that allows gradual release of multiple growth factors, including platelet-derived growth factor (PDGF), transforming growth factor-β (TGF-β), vascular endothelial growth factor (VEGF), and insulin-like growth factor (IGF). However, in 2014, injectable platelet-rich fibrin (I-PRF), which is similar to PRF, was introduced in France by Choukroun, using non-glass tubes and adjusting the centrifugal force. Just like traditional PRF, i-PRF contains high levels of growth factors, stem cells, leukocytes, and cytokines.

These growth factors play a crucial role in angiogenesis, tissue regeneration, modulation of inflammation, and bone remodeling, all of which are central processes in orthodontic tooth movement and periodontal healing.

Inclusion Criteria:

• Adult patients aged between 17 and 28 years
• Class I malocclusion with moderate crowding (4-6 mm) according to Little's Irregularity Index (LII)
• Normal or inclination for mandibular incisors
• Complete permanent teeth.

Exclusion Criteria:

• Previous orthodontic treatment,
• Poor oral hygiene,
• Severe skeletal discrepancy,
• The presence of coagulation disorders or being under anticoagulant treatment.