8. Preparation

Venous blood of patient is drawn into 10 mL, anticoagulant-free tubes and then immediately spun in a tabletop centrifuge at 3000 rpm for 10 min. Due to the lack of anticoagulant, platelet activation occurs once the blood contacts the glass tube walls and subsequently initiates the coagulation cascade. By centrifugation, fibrinogen is concentrated in the top and middle of the tube and then circulating thrombin transforms it into fibrin. This action leads to the development of a fibrin clot in the middle of the tube, between the RBCs at the bottom and serum at the top. The upper straw-colored layer is removed from the centrifuge tube and blotted to remove serum and RBC to result in a dense matrix. Timing is also critical to the success of the PRF technique. PRF must be prepared immediately before application to the surgical site (Figure 1) [1].

8.1.1. PRF in soft tissue regeneration

intact soft tissue coverage.

position [15].

8.1.3. Sinus lift procedure

The use of platelet concentrates may reduce and control the risks associated with delayed bone and soft tissue healing. The success for the healing of a bone graft is certainly related with

The Use of Platelet-Rich Fibrin in Bone Grafting http://dx.doi.org/10.5772/intechopen.79825 99

Patients using antiresorptive therapies exhibit a reduced healing potential in bone and soft tissue that can lead to medication related osteonecrosis. In order to stimulate healing and obtain soft tissue coverage, PRF can be placed to the surgical or exposed area without tension. Even if there

The other indication of PRF usage is the method of socket preservation. When implant restoration is considered after extraction of a tooth, this must be kept in mind that the resorption process starts immediately. Thus, the volume of the socket, soft tissue closure and thickness of gingiva must be protected as possible as early, for a complete and quick bone regeneration. If the wound closure and remodeling are achieved properly, implant can be placed in the desired

Several oral and maxillofacial surgical procedures have used membranes for guided bone regeneration (GBR). The potential applications of PRF in this field have been shown to be effective in different clinical situations. However, this method may not be superior as a barrier membrane for regeneration when compared to conventional membranes, and therefore appropriate cases should be selected in order to benefit from the properties of PRF in GBR (Figure 2) [16, 17].

Sinus lift is one of the most frequent grafting procedures in implantology and has proven to be a successful and predictable technique for providing bone height for implant placement. In the

Figure 2. Enucleation of radicular cyst resulted from left central incisor tooth and apical resection were performed at the same time. A: After eliminating the whole lesions, PRF placed into the intrabony defect to accelerate healing and prevent

soft tissue collapse. B and C: PRF membrane was used to cover the buccal wall of the cavity as a barrier.

is a need for researches in this field, PRF presented valuable solutions till today [15].

8.1.2. Guided bone regeneration (GBR) (as a barrier membrane)

#### 8.1. Clinical applications of PRF in oral surgery

In the past, PRF could be useful for both hemostasis and wound healing. Nowadays, sinus lift technique is considered to be one of the most common and valid procedures for the use of PRF in oral surgery. PRF is also used for augmenting the alveolar ridge, improve soft tissue healing and periodontal regeneration and preserving the alveolar ridge height after extraction. It has been studied that PRF improves wound healing in multiple extractions by reducing healing time [14].

Figure 1. Preparation of PRF membrane. A: Collection of venous blood into the tube; B: centrifuge device; C: platelet-rich fibrin clots; D: PRF clots were pressed to obtain more dense membranes; E: PRF membranes.

#### 8.1.1. PRF in soft tissue regeneration

8. Preparation

Venous blood of patient is drawn into 10 mL, anticoagulant-free tubes and then immediately spun in a tabletop centrifuge at 3000 rpm for 10 min. Due to the lack of anticoagulant, platelet activation occurs once the blood contacts the glass tube walls and subsequently initiates the coagulation cascade. By centrifugation, fibrinogen is concentrated in the top and middle of the tube and then circulating thrombin transforms it into fibrin. This action leads to the development of a fibrin clot in the middle of the tube, between the RBCs at the bottom and serum at the top. The upper straw-colored layer is removed from the centrifuge tube and blotted to remove serum and RBC to result in a dense matrix. Timing is also critical to the success of the PRF technique.

98 Bone Grafting - Recent Advances with Special References to Cranio-Maxillofacial Surgery

PRF must be prepared immediately before application to the surgical site (Figure 1) [1].

In the past, PRF could be useful for both hemostasis and wound healing. Nowadays, sinus lift technique is considered to be one of the most common and valid procedures for the use of PRF in oral surgery. PRF is also used for augmenting the alveolar ridge, improve soft tissue healing and periodontal regeneration and preserving the alveolar ridge height after extraction. It has been studied that PRF improves wound healing in multiple extractions by reducing healing time [14].

Figure 1. Preparation of PRF membrane. A: Collection of venous blood into the tube; B: centrifuge device; C: platelet-rich

fibrin clots; D: PRF clots were pressed to obtain more dense membranes; E: PRF membranes.

8.1. Clinical applications of PRF in oral surgery

The use of platelet concentrates may reduce and control the risks associated with delayed bone and soft tissue healing. The success for the healing of a bone graft is certainly related with intact soft tissue coverage.

Patients using antiresorptive therapies exhibit a reduced healing potential in bone and soft tissue that can lead to medication related osteonecrosis. In order to stimulate healing and obtain soft tissue coverage, PRF can be placed to the surgical or exposed area without tension. Even if there is a need for researches in this field, PRF presented valuable solutions till today [15].

The other indication of PRF usage is the method of socket preservation. When implant restoration is considered after extraction of a tooth, this must be kept in mind that the resorption process starts immediately. Thus, the volume of the socket, soft tissue closure and thickness of gingiva must be protected as possible as early, for a complete and quick bone regeneration. If the wound closure and remodeling are achieved properly, implant can be placed in the desired position [15].

#### 8.1.2. Guided bone regeneration (GBR) (as a barrier membrane)

Several oral and maxillofacial surgical procedures have used membranes for guided bone regeneration (GBR). The potential applications of PRF in this field have been shown to be effective in different clinical situations. However, this method may not be superior as a barrier membrane for regeneration when compared to conventional membranes, and therefore appropriate cases should be selected in order to benefit from the properties of PRF in GBR (Figure 2) [16, 17].

#### 8.1.3. Sinus lift procedure

Sinus lift is one of the most frequent grafting procedures in implantology and has proven to be a successful and predictable technique for providing bone height for implant placement. In the

Figure 2. Enucleation of radicular cyst resulted from left central incisor tooth and apical resection were performed at the same time. A: After eliminating the whole lesions, PRF placed into the intrabony defect to accelerate healing and prevent soft tissue collapse. B and C: PRF membrane was used to cover the buccal wall of the cavity as a barrier.

literature, no application using PRF was more studied than the sinus lift procedure. This model generating to obtain bone height, provides a closed, protected and stable environment for healing. Thus, bone healing in sinus cavity can be evaluated more accurate than the other procedures that are in contact with the oral environment [18].

the implant, it is believed that the main mechanism of peri-implantitis is related to bone/

The Use of Platelet-Rich Fibrin in Bone Grafting http://dx.doi.org/10.5772/intechopen.79825 101

In case of small amount of bone, it is inevitable to make lateral perforation while placing implant or bone resorption around particularly the collar of the implant. In order to reinforce the bone amount around the implant to prevent resorption and gain more esthetic appearance, autogenous and/or synthetic materials can be used to cover the open surface of these implants. Peri-implant bone defects can be developed after immediate implantation (Figure 3). After the insertion of the implant in a fresh avulsion socket, a large peri-implant defect must be filled

For those three clinical situations, bone regeneration between the cavity/defect and implant surface can be achieved by using PRF in addition to bone grafts. With its strong fibrin architecture and specific 3D cell distribution, especially L-PRF may offer positive results when used

Figure 3. Peri-implant bone defect after immediate implant placement. A: Buccal and palatinal bone defects around the implant; B, C: A mix of PRF and xenogeneic bone graft constituted a sticky mass; D, E: PRF with bone graft placed into the

cavity; F: PRF membranes were used to cover the whole defect.

implant interface breakdown [24].

with a material to prevent soft tissue invagination [25].

Subsinus cavity floored by the Schneiderian membrane following sinus lift has a capacity of bone regeneration due to the high osteogenic properties, though several bone materials can yield good results in terms of bone healing [19].

Most researches have focused on bone biomaterials to improve bone quality and to accelerate healing for early operations. The main mechanism of subsinus cavity healing is to be filled with blood clot that is promoting neoangiogenesis and proliferation. Similarly, the aim of using PRF into the cavity is to provide space and optimize healing as a biologic agent [20]. The first study reported on PRF by Choukroun et al. represented that the use of PRF in addition to the bone grafts accelerated healing period for sinus floor augmentation [21]. It is important to reduce healing time before implantation.

The incidence of perforation of the membrane that is a common intraoperative finding was reported ranging from 10 to 60% [22]. The rupture of the membrane can lead to postoperative complications, so has to be repaired before grafting. Otherwise, a biomaterial can migrate into the sinus cavity leading to sinus infection and impairment of healing. Some biomaterials such as collagen membrane and platelet concentrates have been commonly used to prevent these complications. In addition to the use of PRF for grafting, it is also used as an adhesion material and frequently preferred for repair of possible perforations of the schneiderian membrane during sinus lift.

#### 8.1.4. Grafting material for bone regeneration

The acceleration of healing in bone defect is of particular interest when dental implants would be inserted in this area. Due to reduction of time, early functional loading and better primary stability of the implant will be obtained after the regeneration [19]. Thus, some biologic agents may be needed to shorten this period. For this purpose, PRF-like substances can be used. The potential of these substances as a biologic agent in oral and maxillofacial surgery relies on the growth factors stored within platelet alpha granules containing platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF), insulin-like growth factor (IGF), plateletderived angiogenic factor and transforming growth factor-beta (TGF-β). Moreover, PRF acts as a biological connector between different graft elements and serves as a matrix that eases forming new bone tissue into the defect. In fact, due to the lack of standardization and absence of characterization of the studied PRF materials, it is difficult to explain the exact function of platelet concentrates on bone regeneration [23].

#### 8.1.5. PRF for peri-implant bone defects

Peri-implant bone defects are encountered as a result of peri-implantitis and secondly inadequate bone volume for implantation and thirdly immediate implantation. Although the mechanisms of peri-implantitis are considered to be bacterial accumulation or prosthetic overload of the implant, it is believed that the main mechanism of peri-implantitis is related to bone/ implant interface breakdown [24].

literature, no application using PRF was more studied than the sinus lift procedure. This model generating to obtain bone height, provides a closed, protected and stable environment for healing. Thus, bone healing in sinus cavity can be evaluated more accurate than the other

Subsinus cavity floored by the Schneiderian membrane following sinus lift has a capacity of bone regeneration due to the high osteogenic properties, though several bone materials can

Most researches have focused on bone biomaterials to improve bone quality and to accelerate healing for early operations. The main mechanism of subsinus cavity healing is to be filled with blood clot that is promoting neoangiogenesis and proliferation. Similarly, the aim of using PRF into the cavity is to provide space and optimize healing as a biologic agent [20]. The first study reported on PRF by Choukroun et al. represented that the use of PRF in addition to the bone grafts accelerated healing period for sinus floor augmentation [21]. It is important to

The incidence of perforation of the membrane that is a common intraoperative finding was reported ranging from 10 to 60% [22]. The rupture of the membrane can lead to postoperative complications, so has to be repaired before grafting. Otherwise, a biomaterial can migrate into the sinus cavity leading to sinus infection and impairment of healing. Some biomaterials such as collagen membrane and platelet concentrates have been commonly used to prevent these complications. In addition to the use of PRF for grafting, it is also used as an adhesion material and frequently preferred for repair of possible perforations of the schneiderian membrane

The acceleration of healing in bone defect is of particular interest when dental implants would be inserted in this area. Due to reduction of time, early functional loading and better primary stability of the implant will be obtained after the regeneration [19]. Thus, some biologic agents may be needed to shorten this period. For this purpose, PRF-like substances can be used. The potential of these substances as a biologic agent in oral and maxillofacial surgery relies on the growth factors stored within platelet alpha granules containing platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF), insulin-like growth factor (IGF), plateletderived angiogenic factor and transforming growth factor-beta (TGF-β). Moreover, PRF acts as a biological connector between different graft elements and serves as a matrix that eases forming new bone tissue into the defect. In fact, due to the lack of standardization and absence of characterization of the studied PRF materials, it is difficult to explain the exact function of

Peri-implant bone defects are encountered as a result of peri-implantitis and secondly inadequate bone volume for implantation and thirdly immediate implantation. Although the mechanisms of peri-implantitis are considered to be bacterial accumulation or prosthetic overload of

procedures that are in contact with the oral environment [18].

100 Bone Grafting - Recent Advances with Special References to Cranio-Maxillofacial Surgery

yield good results in terms of bone healing [19].

reduce healing time before implantation.

8.1.4. Grafting material for bone regeneration

platelet concentrates on bone regeneration [23].

8.1.5. PRF for peri-implant bone defects

during sinus lift.

In case of small amount of bone, it is inevitable to make lateral perforation while placing implant or bone resorption around particularly the collar of the implant. In order to reinforce the bone amount around the implant to prevent resorption and gain more esthetic appearance, autogenous and/or synthetic materials can be used to cover the open surface of these implants.

Peri-implant bone defects can be developed after immediate implantation (Figure 3). After the insertion of the implant in a fresh avulsion socket, a large peri-implant defect must be filled with a material to prevent soft tissue invagination [25].

For those three clinical situations, bone regeneration between the cavity/defect and implant surface can be achieved by using PRF in addition to bone grafts. With its strong fibrin architecture and specific 3D cell distribution, especially L-PRF may offer positive results when used

Figure 3. Peri-implant bone defect after immediate implant placement. A: Buccal and palatinal bone defects around the implant; B, C: A mix of PRF and xenogeneic bone graft constituted a sticky mass; D, E: PRF with bone graft placed into the cavity; F: PRF membranes were used to cover the whole defect.

in combination with bone biomaterials for the filling of peri-implant bone defects. On the whole, there are still only few studies published in the literature about the use of L-PRF in peri-implant bone defects [26].

References

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The Use of Platelet-Rich Fibrin in Bone Grafting http://dx.doi.org/10.5772/intechopen.79825 103

[2] Dohan DM, Choukroun J, Diss A, et al. Platelet-rich fibrin (PRF): A second-generation platelet concentrate. Part II: Platelet-related biologic features. Oral Surgery, Oral Medicine,

[3] Ehrenfest DMD, Andia I, Zumstein MA, et al. Classification of platelet concentrates (platelet-rich plasma-PRP, platelet-rich fibrin-PRF) for topical and infiltrative use in orthopedic and sports medicine: Current consensus, clinical implications and perspectives.

[4] Ehrenfest DMD, Rasmusson L, Albrektsson T. Classification of platelet concentrates: From pure platelet-rich plasma (P-PRP) to leucocyte- and platelet-rich fibrin (L-PRF). Trends in

[5] Cano-Durán JA, Peña-Cardelles JF, Ortega-Concepción D, et al. The role of leucocyte-rich and platelet-rich fibrin (L-PRF) in the treatment of the medication-related osteonecrosis of the jaws (MRONJ). Journal of Clinical and Experimental Dentistry. 2017;9(8):e1051-e1059

[6] Ehrenfest DMD, Bielecki T, Jimbo R, et al. Do the fibrin architecture and leukocyte content influence the growth factor release of platelet concentrates? An evidence-based answer comparing a pure platelet-rich plasma (P-PRP) gel and a leukocyte- and platelet-rich fibrin

[7] Fioravanti C, Frustaci I, Armellin E, et al. Autologous blood preparations rich in platelets,

[8] Miron RJ, Bishara M, Choukroun J. Basics of platelet-rich fibrin therapy. Dentistry Today.

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[10] Shah R, Triveni MG, Thomas R, et al. An update on the protocols and biologic actions of platelet rich fibrin in dentistry. The European Journal of Prosthodontics and Restorative

[11] Wend S, Kubesch A, Orlowska A, et al. Reduction of the relative centrifugal force influences cell number and growth factor release within injectable PRF-based matrices. Journal

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