Platelet-rich fibrin (PRF) or leukocyte- and platelet-rich fibrin (L-PRF) is a derivative of PRP where autologous platelets and leukocytes are present in a complex fibrin matrix [1] [2] to accelerate the healing of soft and hard tissue [3] and is used as a tissue-engineering scaffold in oral and maxillofacial surgeries. PRF falls under FDA Product Code KST, labeling it as a blood draw/Hematology product classifying it as 510(k) exempt.
To obtain PRF, the required quantity of blood is drawn into test tubes without an anticoagulant and centrifuged immediately. Blood can be centrifuged using a tabletop centrifuge from 3-8 minutes for 1300 revolutions per minute. The resultant product consists of the following three layers: the topmost layer consisting of platelet poor plasma, the PRF clot in the middle, and the red blood cells (RBC) at the bottom. The PRF clot can be removed from the test tube using a pickup instrument (such as Gerald tissue forceps). The RBC layer attached to the PRF clot can be carefully removed using scissors or a blunt instrument. [4]
Platelet activation in response to tissue damage occurs during the process of making PRF release several biologically active proteins including; platelet alpha granules, platelet‑derived growth factor (PGDF), transforming growth factors‑β (TGF‑β), vascular endothelial growth factor (VEGF), and epidermal growth factor. [5] Actually, the platelets and leukocyte cytokines play important parts in role of this biomaterial, but the fibrin matrix supporting them is the most helpful in constituting the determining elements responsible for real therapeutic potential of PRF. Cytokines are immediately used and destroyed in a healing wound. The harmony between cytokines and their supporting fibrin matrix has much more importance than any other platelet derivatives. [6]
Ridge preservation (Colloquially Socket preservation), a procedure to reduce bone loss after tooth extraction to preserve the dental alveolus (containing the tooth socket) in the alveolar bone. A platelet-rich fibrin (PRF) membrane containing bone growth enhancing elements can be stitched over the wound or a graft material or scaffold is placed in the socket of an extracted tooth at the time of extraction. The socket is then directly closed with stitches or covered with a non-resorbable or resorbable membrane and sutured.[ citation needed ]
A platelet-rich fibrin can be used if a sinus lift is required for a dental implant. [7] [8]
Reproduction or reconstitution of a lost or injured part to restore the architecture and function of the periodontium becomes the integral part of comprehensive periodontal therapy. Conventional open flap debridement falls short of regenerating tissues destroyed by the disease. Platelet derived growth factor along with bone morphogenetic proteins are among the most researched growth factors in periodontal regeneration. [9] [10] Platelet rich fibrin showed significant improvement in clinical periodontal parameter as well as in radiograph when compared with open flap debridement alone in a meta analysis. [11] Several bone graft materials have been used in the treatment of infrabony defects. Demineralized freeze dried bone allograft (DFDBA) has been histologically proven to be the material of choice for regeneration. Platelet-rich fibrin has shown significant results comparable to DFDBA for periodontal regeneration. [12] One of the most common aesthetic problem encountered in the field of periodontology is gingival recession, which is perceived by the patients as increase in length of teeth. Though connective tissue graft is a gold standard procedure, PRF can be used as an alternative procedure by keeping patient's comfort in mind. [13]
PRF is used in guided bone and tissue regeneration. [14]
PRF enhances alveolar bone augmentation [15] and necrotic dental pulp and open tooth apex can be revitalized in regenerative endodontics with platelet-rich fibrin. [16]
The third molar, commonly called wisdom tooth, is the most posterior of the three molars in each quadrant of the human dentition. The age at which wisdom teeth come through (erupt) is variable, but this generally occurs between late teens and early twenties. Most adults have four wisdom teeth, one in each of the four quadrants, but it is possible to have none, fewer, or more, in which case the extras are called supernumerary teeth. Wisdom teeth may become stuck (impacted) against other teeth if there is not enough space for them to come through normally. Impacted wisdom teeth are still sometimes removed for orthodontic treatment, believing that they move the other teeth and cause crowding, though this is not held anymore as true.
The periodontal ligament, commonly abbreviated as the PDL, is a group of specialized connective tissue fibers that essentially attach a tooth to the alveolar bone within which it sits. It inserts into root cementum on one side and onto alveolar bone on the other.
Dental alveoli are sockets in the jaws in which the roots of teeth are held in the alveolar process with the periodontal ligament. The lay term for dental alveoli is tooth sockets. A joint that connects the roots of the teeth and the alveolus is called gomphosis. Alveolar bone is the bone that surrounds the roots of the teeth forming bone sockets.
Bone grafting is a surgical procedure that replaces missing bone in order to repair bone fractures that are extremely complex, pose a significant health risk to the patient, or fail to heal properly. Some small or acute fractures can be cured without bone grafting, but the risk is greater for large fractures like compound fractures.
A dental extraction is the removal of teeth from the dental alveolus (socket) in the alveolar bone. Extractions are performed for a wide variety of reasons, but most commonly to remove teeth which have become unrestorable through tooth decay, periodontal disease, or dental trauma, especially when they are associated with toothache. Sometimes impacted wisdom teeth cause recurrent infections of the gum (pericoronitis), and may be removed when other conservative treatments have failed. In orthodontics, if the teeth are crowded, healthy teeth may be extracted to create space so the rest of the teeth can be straightened.
The alveolar process or alveolar bone is the thickened ridge of bone that contains the tooth sockets on the jaw bones. The structures are covered by gums as part of the oral cavity.
Maxillary sinus floor augmentation is a surgical procedure which aims to increase the amount of bone in the posterior maxilla, in the area of the premolar and molar teeth, by lifting the lower Schneiderian membrane and placing a bone graft.
Gingival recession, also known as gum recession and receding gums, is the exposure in the roots of the teeth caused by a loss of gum tissue and/or retraction of the gingival margin from the crown of the teeth. Gum recession is a common problem in adults over the age of 40, but it may also occur starting in adolescence, or around the age of 10. It may exist with or without concomitant decrease in crown-to-root ratio.
Concrescence is an uncommon developmental condition of teeth where the cementum overlying the roots of at least two teeth fuse together without the involvement of dentin. Usually, two teeth are involved with the upper second and third molars being most commonly fused together. The prevalence ranges 0.04–0.8% in permanent teeth, with the incidence being highest in the posterior maxilla.
“Lateral periodontal cysts (LPCs) are defined as non-keratinised and non-inflammatory developmental cysts located adjacent or lateral to the root of a vital tooth.” LPCs are a rare form of jaw cysts, with the same histopathological characteristics as gingival cysts of adults (GCA). Hence LPCs are regarded as the intraosseous form of the extraosseous GCA. They are commonly found along the lateral periodontium or within the bone between the roots of vital teeth, around mandibular canines and premolars. Standish and Shafer reported the first well-documented case of LPCs in 1958, followed by Holder and Kunkel in the same year although it was called a periodontal cyst. Since then, there has been more than 270 well-documented cases of LPCs in literature.
Guided bone regeneration (GBR) and guided tissue regeneration (GTR) are dental surgical procedures that use barrier membranes to direct the growth of new bone and gingival tissue at sites with insufficient volumes or dimensions of bone or gingiva for proper function, esthetics or prosthetic restoration. Guided bone regeneration typically refers to ridge augmentation or bone regenerative procedures; guided tissue regeneration typically refers to regeneration of periodontal attachment.
Hessam Nowzari is the Director of the University of Southern California Advanced Periodontics program, since 1995, and is a diplomate of the American Board of Periodontology.
Platelet-rich plasma (PRP), also known as autologous conditioned plasma, is a concentrate of platelet-rich plasma protein derived from whole blood, centrifuged to remove red blood cells. Though promoted to treat an array of medical problems, evidence for benefit is mixed as of 2020, with some evidence for use in certain conditions and against use in other conditions.
A fibrin scaffold is a network of protein that holds together and supports a variety of living tissues. It is produced naturally by the body after injury, but also can be engineered as a tissue substitute to speed healing. The scaffold consists of naturally occurring biomaterials composed of a cross-linked fibrin network and has a broad use in biomedical applications.
A barrier membrane is a device used in oral surgery and periodontal surgery to prevent epithelium, which regenerates relatively quickly, from growing into an area in which another, more slowly growing tissue type, such as bone, is desired. Such a method of preventing epithelial migration into a specific area is known as guided tissue regeneration (GTR).
Socket preservation or alveolar ridge preservation is a procedure to reduce bone loss after tooth extraction. After tooth extraction, the jaw bone has a natural tendency to become narrow, and lose its original shape because the bone quickly resorbs, resulting in 30–60% loss in bone volume in the first six months. Bone loss, can compromise the ability to place a dental implant, or its aesthetics and functional ability.
A Sinus implant is a medical device that is inserted into the sinus cavity. Implants can be in conjunction with sinus surgery to treat chronic sinusitis and also in sinus augmentation to increase bone structure for placement of dental implants.
Tooth replantation is a form of restorative dentistry in which an avulsed or luxated tooth is reinserted and secured into its socket through a combination of dental procedures. The purposes of tooth replantation is to resolve tooth loss and preserve the natural landscape of the teeth. Whilst variations of the procedure exist including, Allotransplantation, where a tooth is transferred from one individual to another individual of the same species. It is a largely defunct practice due to the improvements made within the field of dentistry and due to the risks and complications involved including the transmission of diseases such as syphilis, histocompatibility, as well as the low success rate of the procedure, has resulted in its practice being largely abandoned. Autotransplantation, otherwise known as intentional replantation in dentistry, is defined as the surgical movement of a tooth from one site on an individual to another location in the same individual. While rare, modern dentistry uses replantation as a form of proactive care to prevent future complications and protect the natural dentition in cases where root canal and surgical endodontic treatments are problematic. In the modern context, tooth replantation most often refers to reattachment of an avulsed or luxated permanent tooth into its original socket.
Gingival grafting, also called gum grafting or periodontal plastic surgery, is a generic term for the performance of any of a number of periodontal surgical procedures in which the gum tissue is grafted. The aim may be to cover exposed root surfaces or merely to augment the band of keratinized tissue.
