Growth Factors Release of PRF and PRGF
Condition: Periodontitis
MeSH terms: Periodontitis
Study type: Interventional
Phase: Phase 3

Summary: 
      Background: platelet concentrate could enhance growth factors (GF) crevicular fluid levels
      which might be crucial to proper tissue repair and wound healing. However, the open usually
      contaminated nature of periodontal defects could affect negatively GF availability and
      activity. To test this assumption, this study was designed to evaluate levels of VEGF and
      PDGF-BB in gingival crevicular fluid (GCF) during the early stages of healing of localized
      intrabony defects treated with platelet rich in growth factor (PRGF) and platelet rich fibrin
      (PRF) as compared with xenograft defect filling control.

      Methods: Thirty non-smoking patients with severe chronic periodontitis participated in this
      prospective, randomized and single blinded trial. Each patient contributed one interproximal
      defect that was randomly assigned to the bone substitute grafting control (n=10) G1,
      experimental PRGF (n=10) G2 and PRF (n=10) G3. Plaque index, gingival index, probing depth
      (PD), clinical attachment level (CAL) and the intrabony depth of the defect (IBD) were
      measured at baseline for patient enrollment. Gingival crevicular fluid (GCF) samples were
      collected on days 1 and 3, 7, 14, 21, and 30 days after therapy. The primary outcome variable
      was the change in VEGF and PDGF-BB levels for sites treated by PRGF and PRF compared to that
      of the xenograft treated cases.
    

Detailed description: 
      Owing to the lots of challenges that facing the use of recombinant growth factors in
      periodontal therapy, it is important to look for an alternative that combine ease of
      preparation and physiologic mode of delivery. Platelet concentrate has been developed for
      this purpose with many debates about the duration of GF availability in the defect area.
      Platelet-rich fibrin (PRF) is a leucocyte- and platelet-rich fibrin biomaterial. This dense
      fibrin membrane was claimed to releases high quantities of three main growth factors
      (Transforming Growth Factor b-1 (TGFβ-1), platelet derived growth factor AB, PDGF-AB;
      vascular endothelial growth factor, VEGF) and an important coagulation matricellular
      glycoprotein (thrombospondin-1, TSP-1). It has a natural fibrin framework that can protect
      growth factors from proteolysis. It is shown that PRF can release growth factors gradually
      and keep their activity to a relatively long period compared with platelet rich plasma (PRP).
      Levels of released TGF-1 and PDGF-AB markedly increased and reached the highest amount at day
      , then decreased mildly. In contrast, PRP experienced uncontrollable and short-term release
      of TGF-1 and PDGF-AB, which reached the highest amount at day 1 and then decreased
      rapidly.Clinically, it was found that PRF can improve clinical parameters associated with
      human intrabony periodontal defects and BPBM (bovine porous bone mineral) has the ability to
      augment effects of PRF in reducing pocket depth, improving clinical attachments levels, and
      promoting defect fill. On the other hand studies reported similar PD (probing depth)
      reduction, CAL (clinical attachment level) gain, and bone fill at sites treated with PRF or
      PRP compared with conventional open flap debridement.

      Preparation rich in growth factors (PRGF-Endoret) technology was claimed to circumvent many
      of the limitations of other reported platelet-rich preparations. Sodium citrate and calcium
      chloride are used as an anticoagulant and a clot activator, respectively. Addition of calcium
      chloride promotes the formation of native thrombin, mimicking the physiological clotting
      process and enabling a more sustained release of growth factors, which might be crucial to
      proper tissue repair and wound healing. Moreover, this procedure obviates immunological
      reactions and the risk of disease transmission associated with the use of exogenous bovine
      thrombin. Anitua et al reported that PRGF contains a moderately elevated platelet
      concentration of ~6x105 platelets, which has been reported to induce the optimal biological
      benefit. Lower platelet concentrations can lead to suboptimal effects, whereas higher
      concentrations might have an inhibitory effect. PRGF application after extraction improved
      the healing process in diabetic patients by accelerating socket closure (epithelialization)
      and tissue maturation, proving the association between PRGF use and improved wound healing in
      diabetic patients.

      In the present study it was proposed that the opened, constantly contaminated nature
      periodontal defects could be a source of continuous catabolic bacterial and tissue enzymes
      and binding proteins that affect platelet concentrate contained GF availability and activity.
      To confirm this assumption, this study was designed to evaluate levels of platelet derived
      growth factor - BB (PDGF-BB) and vascular endothelial cell growth factor (VEGF) in GCF during
      the early stages of healing for sites treated with PRF and PRGF in intrabony periodontal
      defects and to correlate GF levels with the clinical findings. This could figure out the
      potentials of these 2 commonly used platelet concentrate in the periodontal defects ecology.
    

Intervention name(s): group 1 bio-oss bone xenograft; group 2 platelet rich in growth factor (autogenous platelet rich in growth factor); group 3 platelet rich fibrin (autogenous platelet rich fibrin)
Intervention type(s): Procedure; Procedure; Procedure
Intervention description(s): bone substitute (bio-oss); platelet rich in growth factor (autogenous platelet rich in growth factor); platelet rich fibrin (autogenous platelet rich fibrin)
Other intervention name(s): bio-oss bone xenograft; PRGF; PRF
Intervention MeSH terms: Mitogens
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Treatment