2. Pure platelet-rich fibrin (P-PRF)

Pure platelet-rich fibrin (P-PRF) in other terms leukocyte-poor platelet-rich fibrin is a preparation without leukocytes having a high-density fibrin network. This platelet concentrate exists in a strongly activated gel form. It cannot be injected and used like traditional fibrin glues. On the other hand, with its strong fibrin matrix facility, P-PRF can be handled like a real solid material for several applications [3].

5. Injectable platelet-rich fibrin (i-PRF)

6. Titanium prepared platelet-rich fibrin (T-PRF)

shredded PRF clot [10].

the T-PRF application [10].

7. Prepared platelet-rich lysate (PRF-L)

One of the recent developments in the PRF technology is injectable PRF (i-PRF). Standard PRF is prepared as a gel which is inconvenient to inject [10]. i-PRF protocol necessitates short centrifugation period in order to produce a liquid platelet concentrate, which includes primarily liquid fibrinogen and thrombin prior to fibrin formation [11]. The plastic tubes with hydrophobic surface are used, and therefore coagulation process does not effectively start. Hence, all the blood components reach the top of the tube under the centrifugation force with short centrifugation time (i.e., 2–4 min). The light yellow-colored layer, which is the combination of plasma and platelets, is aspirated from the top of the tube to obtain i-PRF. Nowadays, it is used with bone grafts to keep graft particles tightly encapsulated in the fibrin matrix. With the coagulation process, i-PRF forms a gel consistency holding bone graft together. Also, the release of growth factor is beneficial for the graft. This has the potential to convert any osteoconductive graft to osteopromotive, which would provide faster and better bone formation. Another type of graft prepared with i-PRF is the PRF block. For its preparation, i-PRF is mixed with a combination of bone graft and

The Use of Platelet-Rich Fibrin in Bone Grafting http://dx.doi.org/10.5772/intechopen.79825 97

Some physicians worry about damage for the patient with glass-evacuated blood collection tubes with silica activators. O'Connell emphasized that silica contact cannot be avoided with glass tubes. These silica particles are dense enough to settle in the sediment and might reach the patient when the product is used during procedures [12]. Recently, Tunali et al. used medical grade titanium tubes to produce titanium prepared platelet-rich fibrin (T-PRF) [10]. This biocompatible material was tried to eliminate the potential negative effects of silica from dry glass or glass-coated plastic tubes [12]. The research showed that T-PRF supply is a more organized network than L-PRF. Furthermore, its fibrin network covers larger area and has thicker fibrin clot. In a human study, wound healing in the palatal mucosa is found better with

A newer application of PRF is the prepared platelet-rich lysate (PRF-L). In this technique, after PRF preparation, it is incubated at 37C in a humidified atmosphere of 5% CO2 and 95% air. The exudate, which is collected, is referred to as PRF lysate. It is said to be a good source of several growth factors. In a study, it is found that PRF-L can significantly improve the proliferation index, collagen deposition and migration rates in chronically UVA-irradiated human

dermal fibroblasts [13]. This is a new technique that requires further studies.

During preparation, only very low amounts of leucocytes are collected because of the specific separator gel, which is used to obtain P-PRF. However, the platelet collection level is high, and the preservation of the platelets during the procedure seems to be acceptable [4]. The main disadvantage of this platelet concentrate protocol is its cost and complex procedure if it is compared to the other forms of PRF, which are available nowadays [3].