INTRODUCTION:

It is common that the time period to complete the orthodontic treatment varies from the minimum of 18 months to the maximum of 36 months.¹ Prolonged orthodontic treatment can be associated with complications such as poor patient compliance, poor oral hygiene which leads to gingival problems, decreased patient satisfaction and iatrogenic effects such as white spot lesions, external root resorption and possibly loss of teeth.² Why should we wait such a long period for the treatment to be completed?

Thus, finding a method to accelerate orthodontic treatment (OTM) that is safe and predictable with patient compliance which does not compromise the treatment result, remains at the priority in research and innovation in the field of orthodontics.³

Many clinical trials have established to decrease the duration of orthodontic treatment with different methods by modifying the biological response of tissue including surgical, pharmaceutical, physical, laser, electromagnetic and other methods.1,4

Platelet-based preparations from the patient’s blood provide a safe alternative to commercially available bioactive materials.⁴

PRF, a completely autologous fibrin matrix, was developed as a second generation platelet concentrate without the addition of anticoagulants and additives at lower centrifugation speeds. PRF is easily applied, minimally invasive, repeatable, autogenous, low cost, and a complication avoiding procedure.¹

Injectable platelet rich fibrin (i-PRF) is a rich source of platelets during bone healing and provides an increased concentration of gingival crevicular fluid (GCF). Wang et al reported that i- PRF affected osteoblastic behaviour remarkably by influencing its migration, proliferation, and differentiation. This promotes cellular activity and accelerates bone turnover and healing.⁴

The leukocyte-platelet-rich fibrin (L-PRF) has been termed as the second-generation platelet concentrate. The L-PRF composed of a 3- dimensional fibrin matrix that traps a variety of blood cells. The L-PRF is enriched with autologous platelets, growth factors, cytokines, and leukocytes that direct the various cells in local tissue remodeling by promoting extracellular matrix synthesis, cell proliferation and differentiation, angiogenesis, and chemotaxis.⁵

      Need for study:

It has been already proven that both i-PRF and L- PRF accelerates orthodontic tooth movement but the maximum effect is seen in first 6 weeks. The purpose of this study is to compare whether a two stage injectable platelet rich fibrin (i-PRF) provides extended and faster orthodontic treatment compared to that of Leukocyte-platelet- rich fibrin followed by injectable platelet rich fibrin (i-PRF) during en-masse retraction. It also gives a direct comparison of the effect of i-PRF and L-PRF on the rate of orthodontic tooth movement in the first stage