RU2806005C1 - Method for manufacturing multilayer autogenous fibrin membrane - Google Patents

Abstract

FIELD: medicine; chemistry.

SUBSTANCE: invention is related to a method for manufacturing a multilayer autogenous fibrin membrane, according to which blood is taken from the patient’s ulnar vein, then an autogenous fibrin clot is obtained from the resulting blood by centrifugation, after which the clot is squeezed out, which allows to obtain an autogenous fibrin membrane, then the autogenous fibrin membrane is impregnated with liquid fibrinogen, having previously carried out linear perforations of its surface, then a multilayer autogenous fibrin membrane is formed from the autogenous fibrin membrane.

EFFECT: possibility of promptly manufacturing a multilayer autogenous fibrin membrane and placing it in the wound area, with ability to give the membrane the desired thickness and shape, optimize tissue regeneration processes and reduce treatment time.

11 cl, 8 ex

Description

The claimed invention relates to the field of medicine, in particular to regenerative medicine and dentistry, and can be used for targeted bone regeneration during osteoplastic surgery, plastic surgery of soft tissues in the oral cavity, and other reconstructive interventions aimed at restoring tissue volume, functions and aesthetics of the dentition.

Ensuring complete wound healing and accelerating regenerative processes remains the most important task of surgical dentistry and maxillofacial surgery, significant for the treatment of both somatically intact patients and individuals with compromised systemic health. Today, multilayer membranes for targeted tissue regeneration are of particular interest to surgeons and development researchers (De Risi et al., 2015).

For the manufacture of membranes, both biodegradable and non-biodegradable materials are used. There is a known method for forming a membrane based on a non-biodegradable polymer material, polyethylene terephthalate. Polytetrafluoroethylene, dense in its consistency, can be used during procedures for guided bone regeneration or guided tissue regeneration. It prevents tissue germination and does not cause its rejection by the body (Usher, Wallace, 1958). In particular, the membrane [1] is made on the basis of polyethylene terephthalate in the form of two layers. The thickness of one of the layers is 1 mm with a porosity of 90%. This layer prevents epithelial migration, stabilizes the wound and promotes connective tissue formation (Scantlebury 1993). The second layer, 0.15 mm thick and 30% porosity, serves as a barrier to the gingival valve (Sigurdsson et al., 1994). However, this membrane has a number of significant disadvantages, for example, insufficient permeability of the membrane for nutrients, as a result, disruption of the nutrition of surrounding tissues. But the main disadvantage of membranes based on non-biodegradable polymers is the need for repeated surgery to remove them, which can further lead to complications (Cortellini et al., 1990).

Another known method of membrane formation is the use of extracellular matrix proteins, in particular, collagens of various types. Collagen membranes have a number of important advantages, such as good biocompatibility, the ability to undergo rapid vascularization, low immunogenicity, and high cell adhesiveness (Klinger et al., 2014). There is a known method [2] for producing a collagen membrane, which is plates of type I collagen obtained from the peritoneal membrane of calves or pigs and saturated with sulfated glycosaminoglycans - hyaluronic acid, chondroitin-6-sulfate, keratin sulfate, dermatan sulfate. The method for preparing this membrane is to apply a paste of type II collagen to a surface of type I collagen, followed by freeze-drying, resulting in a two-layer structure having one dense and the other loose spongy layer. This membrane is used in targeted tissue regeneration as an isolating membrane during the surgical restoration of bone defects (any kind of destruction of bone tissue, when removing cysts and tumors from bone tissue, etc.), as a plastic material in surgical dentistry, maxillofacial surgery, and also as a carrier of biologically active substances, drugs and cells.

Its disadvantage is that when the bone defect is closed, the membrane swells. This can lead to wound opening and infection, fairly rapid resorption and loss of mechanical functions even before bone tissue is formed. Xenografts also carry risks of zoonotic disease transmission, and graft rejection is more likely.

However, today the “gold standard” in regenerative medicine, and dentists, is the use of autograft, due to its high regenerative potential. To improve and accelerate the regeneration of bone structures and soft tissues, clinicians are of great interest in the use of drugs obtained, for example, based on PRP (platelet-rich blood plasma) preparations; moreover, the growth factors and cytokines contained in PRP have pronounced reparative properties [ 2, 4]. Thus, the results obtained by dental surgeons, periodontists and maxillofacial surgeons using such drugs demonstrate a pronounced clinical effect in the restoration of soft and hard periodontal tissues [5-7].

One of these products is PRF (platelet-rich fibrin or L-PRF (leukocyte- and platelet-rich fibrin), a platelet-rich fibrin obtained from the patient’s blood plasma, which is a dense fibrin network enriched in platelets and leukocytes [8]. L-PRF , due to its structural features, provides not only the long-term release of growth factors (VEGF, IGF1, PDGF - AB) and cytokines (IL-1b), but also ensures pronounced cell migration [9] and osseointegration, which is clinically manifested by faster healing of the operated hard and soft tissues and reduction of postoperative discomfort [7, 10].L-PRF has also been shown to be highly biocompatible with patient tissues, since it is obtained from autogenous biomaterial - the patient’s blood without the use of anticoagulants [11].

The closest known method is the method for preparing L-PRF membranes [12]. However, traditionally prepared membranes have a number of disadvantages. In the process of “squeezing out” fibrin clots, despite the increase in the concentration of material per unit area and compaction of the structure, the future membrane significantly loses in thickness. Its use in work is complicated due to its fragility and susceptibility to deformation. When trying to lay membranes layer by layer, due to the natural properties of fibrin, they are easily deformed and stick together without giving a significant increase in thickness, which makes their use not ergonomic.

The purpose of the claimed invention is to eliminate these shortcomings and improve the quality of treatment of diseases that require targeted tissue regeneration, as well as operational manufacturability.

This goal is achieved as follows: a method for producing an autogenous fibrin membrane, which includes the following sequence of operations: first, blood is taken from the patient's ulnar vein, then an autogenous fibrin clot is obtained from the resulting blood by centrifugation, after which the clot is squeezed out, obtaining an autogenous fibrin membrane characterized by: in that the autogenous fibrin membrane is impregnated with liquid fibrinogen, having previously carried out linear perforations of its surface, then a multilayer structure is formed from the autogenous fibrin membrane, and then placed in the wound area.

The manufacturing method can in particular be characterized in that an autogenous fibrin membrane is obtained by squeezing out the exudate.

The manufacturing method may in particular be characterized in that the exudate is squeezed out using a Pritchard dissolver.

The manufacturing method, in particular, can be characterized by squeezing out the exudate using a press.

The manufacturing method, in particular, can be characterized in that a multilayer structure of an autogenous fibrin membrane is formed by folding it, and the flat part of the multilayer autogenous fibrin membrane is pressed out after each folding.

The manufacturing method, in particular, can be characterized by forming a multilayer structure of an autogenous fibrin membrane by folding it, while impregnating the multilayer autogenous fibrin membrane with liquid fibrinogen before each folding.

The manufacturing method, in particular, can be characterized by forming a multilayer structure of an autogenous fibrin membrane by stacking autogenous fibrin membranes on top of each other, with each subsequent autogenous fibrin membrane being compressed with the previous ones.

The manufacturing method may in particular be characterized in that the autogenous fibrin clot obtained by centrifugation is placed on a sanitized flat surface.

The manufacturing method, in particular, can be characterized by the fact that blood is taken from the patient's cubital vein in a volume of 30 to 200 ml.

The method for manufacturing a multilayer autogenous fibrin membrane is carried out as follows

Native blood is taken from the patient's cubital vein, depending on the configuration of the proposed autogenous fibrin material, from 30 ml to 200 ml. Then, using a specialized centrifuge according to the instructions proposed by the manufacturer, PRF is obtained in the form of a clot. The use of only autologous components eliminates the risk of graft rejection or any other immune reactions, which improves the quality of healing. The fibrin clot, separated from the red blood cell mass, is placed on a sanitized flat surface and gently squeezed out of excess exudate. It is preferable to completely remove the exudate by placing it under a press (for example, using Surgident PRF Fibrin Membrane Boxes, Scilogex BOX PRF and similar structures). A flat, sanitized surface allows you to obtain a clean autogenous fibrin membrane of the desired shape. The press provides optimal pressure on the membrane to obtain the required properties that ensure the highest degree of engraftment of the finished autogenous fibrin material. Excess exudate is also squeezed out using a Pritchard rasp, which provides greater flexibility in the process of preparing autogenous fibrin material to give the required shape, most suitable for the anatomical parameters of the post-extraction hole, which improves the quality of healing of the postoperative bone wound. The approximate thickness of the finished autogenous fibrin membrane is 1-2 mm. Then, in the resulting single-layer autogenous fibrin membrane, linear perforations are created with a scalpel, and the autogenous fibrin membrane is impregnated with liquid fibrinogen. Due to the use of fibrin enriched with leukocytes and platelets in the treatment process, and thanks to the growth factors contained in platelets, tissue regeneration processes are optimized and treatment time is reduced. Creation of perforations is necessary for improved absorption of liquid fibrinogen into the graft material and increased consolidation of the membrane. Next, a second layer of similarly prepared membrane is placed on top; excess exudate is squeezed out again. Depending on the clinical need, a multilayer structure can be obtained by folding (in half) the prepared membrane, also with subsequent removal of excess exudate. Additionally, depending on the clinical need, obtaining a multilayer structure can be combined by, for example, superimposing the prepared membranes on top of each other, removing excess exudate by applying compression, creating linear perforations, impregnating with liquid fibrinogen and folding in half, and then removing excess exudate. These examples of obtaining a multilayer structure do not limit the invention. Methods for producing a multilayer structure can combine various options within the scope of the presented claims. Depending on the clinical need, the number of layers can reach 8 or more. Impregnation with liquid fibrinogen, creation of linear perforations and compression of the flat part of the membrane should be carried out on each subsequent layer. As a result of manipulations, glued fibrin sheets and conglomerates of fibrin threads are obtained, which are easily removed or drawn into the membrane itself. The membranes remain ready for use for 2.5-3 hours, provided they are constantly moistened with exudate.

The technological effectiveness of the operation lies in the possibility of prompt production of a multilayer autogenous fibrin membrane by a dental surgeon and placing it in the wound area. The small number of manipulations in the manufacture of the inventive membrane increases convenience and makes it quite easy to introduce the use of multilayer autogenous fibrin membranes in daily practice. The speed of production of the inventive membrane makes it possible to reduce the operation time. The ability to give the membrane the desired thickness and shape ensures the most optimal filling of the wound. Reducing the time of surgical intervention reduces recovery time and improves the quality of postoperative wound healing.

The advantage of this method is the creation of significantly greater thickness and volume than separately folded membranes due to the combination of L-PRF fibrin with liquid fibrinogen. Increased efficiency and reliability of the structure of the multilayer L-PRF membrane is ensured for its further use as a basis for targeted regeneration of oral tissues. The use of only autologous components eliminates the risk of developing transplant rejection or any other immune reactions, which also ensures high regenerative potential. This ensures low invasiveness of the collection of the autogenous biomaterial used. Due to the use of fibrin membrane in the treatment process, tissue regeneration processes are optimized and treatment time is reduced.

The invention has a consistency convenient for surgical intervention, which determines its manufacturability. The use of the proposed method in surgical practice has shown a reduction in time and facilitation of postoperative rehabilitation. Ease of learning and simplicity of manipulation, coupled with low cost, make it possible to introduce the proposed method into the daily practice of a dental surgeon, ensuring high reproducibility of the manufacturing technique.

The inventive method is illustrated in the description of the following clinical cases:

Clinical case 1 with the use of a multilayer autogenous fibrin membrane as part of an operation for tooth extraction and open wound closure

Patient K. came to the clinic with complaints of discomfort and pain in the distal part of the lower jaw in the area of the 4.7 tooth and a long-term absence of teeth in the chewing sections in all segments. On examination: 1.3, 1.5, 1.6, 1.7, 2.5, 2.7, 3.6, 3.7 and 4.6 dental units are missing. In the area of 4.7 teeth there are signs of a chronic inflammatory process. Extended bridge-like orthopedic structures supported by 1.2-1.4; 2.4-2.6; 3.4 and 3.5; 4.4, 4.5-4.7. Somatically healthy.

Diagnosis: K08.1 Secondary partial adentia. By 06.84 Partial ridge atrophy. K08.2 Atrophy of the edentulous alveolar margin. Based on the results of the examination and radiography (CBCT and OPTG), it was proposed to remove the orthopedic structure and remove the socket of the 4.7 tooth with preservation. In the area of missing 1.3, 1.5, 1.6, 1.7, 2.5, 2.7, 3.6, 3.7 and 4.6, carry out dental implantation and subsequent prosthetics, including replacement of old orthopedic extended bridge structures.

Surgery protocol: Before the operation begins, pain relief is performed using local anesthesia. A gentle, careful separation of adjacent soft tissues from the orthopedic structure is performed. Tooth extraction forceps are used to remove the metal crown. Then, using an ultrasonic instrument, the tooth is divided into parts and all fragments are sequentially extracted. After all parts of the tooth are extracted, granulation tissue is removed, the socket is revised, and its antiseptic treatment is performed. Next, the socket is preserved with any osteoplastic material - the choice depends on the doctor’s preferences. Collagen containing material is placed on top of the bone graft, which can also be covered with an antiseptic iodine-containing dressing.

Next, the operator begins to create a multilayer autogenous fibrin (L-PRF) membrane from previously taken venous blood, in a volume of 80 ml, which will be used to fill the socket of the extracted tooth.

The fibrin clot obtained during the centrifugation process and separated from the red blood cell mass is placed on a flat surface and delicately squeezed out of excess exudate by placing it under a press, for example, using a Pritchard dissolver.

Then, linear perforations are created in the resulting single-layer membrane with a scalpel, and the membrane is impregnated with liquid fibrinogen. The prepared membrane is folded into an envelope and excess exudate is squeezed out. The resulting multilayer (three layers) membrane is placed in the wound area as a finishing material to fill the hole of the extracted tooth and promote better healing. At the end of the operation, the wound is sutured with regular and/or approximating sutures and absorbable suture material, for example, Catgut material, diameter 5/0.

Postoperative observation: 30 minutes after the operation, the oral cavity and the closed surgical wound are examined. To control the quality of the intervention, a radiography study (OPTG) was performed. The results of the study show that tooth 4.7 was completely removed, there were no cavities or voids at the location of the tooth roots.

After surgery it is recommended: antibacterial therapy - 7-10 days; local use of antiseptics, for example, a solution of chlorhexidine 0.05% or furacilin; physical rest for the first 3 days.

When examining Patient K. on the 14th day after surgery, her face was symmetrical, there were no hematomas, bruises, or drainages. Nasal breathing is not impaired. The mouth is opened fully. The sutures in the area of the intervention are partially intact; locally there is slight swelling. The edges of the wound are covered with fibrin film. Complaints: discomfort from stitches. There are no other complaints. A decision was made to remove the remaining sutures.

Upon examination of Patient K. on day 21: the face is symmetrical, there are no hematomas, bruises, drainages, or soft tissue swelling. Nasal breathing is not impaired. The mouth is opened fully. In the operated area, complete healing of the wound surface is noted. No complaints.

Clinical case 2 with the use of a multilayer autogenous fibrin membrane as part of a simultaneous operation - surgery for tooth extraction and horizontal augmentation of the alveolar process

Patient G. came to the clinic with complaints of discomfort and pain in the distal part of the lower jaw in the area of 4.7 and 4.5 teeth and a long-term absence of teeth in the same part. On examination: in segment 1 there are no 1.4 and 1.5, dental units from 1.2 to 1.6 inclusive, a one-piece orthopedic bridge structure; in the 2nd segment of the jaw, 2.1 teeth are missing, 2.4, 2.5, 2.6 and 2.7 dental units are replaced by dental implants with temporary orthopedic structures, 1.1, 2.1, 2.2 and 2.3 - a bridge; in the 3rd segment of the jaw in the area of 3.5, 3.6 and 3.7 - orthopedic structures supported by dental implants are installed; 4.4 and 4.6 dental units are missing, and in the 4th segment an extended bridge is installed, including 4.3 - 4.7 dental units. In the area of 4.5 and 4.7 teeth there are signs of a chronic inflammatory process. Somatically healthy.

Diagnosis: K08.1 Secondary partial adentia. K06.84 Partial ridge atrophy. K08.2 Atrophy of the edentulous alveolar margin. Based on the results of the examination and radiography (CBCT and OPTG), it was proposed to remove the orthopedic structure and remove with preservation the sockets of teeth 4.5 and 4.7 with the simultaneous implementation of the first stage of horizontal augmentation of the alveolar process in the area of the 4.6 tooth using a two-stage reconstruction of the alveolar ridge (according to the author’s patent No. RU 2758903) for subsequent installation of dental implants and prosthetics. Replace old orthopedic extended bridge structures with orthopedic restorations supported by dental implants in areas 1.4 and 1.5, 2.1.

Operation protocol: Before the operation begins, pain relief is performed using local anesthesia and the orthopedic structure is removed. Along the crest of the alveolar process, an incision is made into the soft tissues down to the bone and careful separation of the adjacent soft tissues from the 4.5 and 4.7 teeth. Then, along the entire perimeter in the area of surgical interest, the flap is mobilized and the full-thickness mucoperiosteal flap is displaced vestibularly.

Tooth extraction forceps are used to extract 4.5 teeth. Then, using an ultrasonic instrument, the 4.7 tooth is divided into parts and all fragments are sequentially extracted. After extracting all parts of the tooth, granulation tissue is removed, sockets 4.5 and 4.7 of the extracted teeth are inspected, and they are treated with antiseptic.

After this, in the area of the missing 4.6 tooth on the exposed jawbone, markings are made to indicate the boundaries of the cut. On the vestibular side, according to given landmarks, cuts are made to the alveolar ridge, which mark the boundaries of future splitting - augmentation.

Next, the operator begins to create a multilayer L-PRF membrane from previously taken venous blood in a volume of 200 ml, which will be used to fill the socket of the extracted tooth and close the alveolar ridge after cuts have been made from the vestibular side and along the ridge.

Next, the fibrin clot separated from the red blood cell mass is placed on a flat surface and gently squeezed out of excess exudate, for example, using a Pritchard dissolver. Then, linear perforations are created in the resulting single-layer membrane with a scalpel, and the membrane is impregnated with liquid fibrinogen. The prepared membrane is folded in half, the excess exudate is squeezed out, then the membrane is soaked in liquid fibrinogen, after which it is folded in half, the excess exudate is squeezed out.

Next, the sockets of the removed 4.5 and 4.7 teeth are preserved using any osteoplastic material - the choice depends on the doctor’s preferences. Collagen containing material is placed on top of the bone graft, which can also be covered with an antiseptic iodine-containing dressing. The resulting cuts in the area of 4.6 teeth are filled with collagen sponge.

The resulting multilayer (four layers) membrane is placed in the wound area as a finishing material for filling the hole of the extracted 4.7 tooth. On the vestibular side, a similarly prepared multilayer (four layers) autogenous fibrin membrane is also placed on the alveolar process. Then a full-thickness mucoperiosteal flap is placed in place and after that the operated area is closed - the wound is sutured with regular and/or H-shaped sutures, absorbable suture material, for example, “Catgut” material, diameter 5/0. The simultaneous operation is completed by finishing filling the socket of the 4.5 tooth with a multilayer (four layers) membrane prepared according to the method described above, and the edges of the wound are sutured in a similar way.

Postoperative observation: 30 minutes after surgery, the oral cavity and the closed surgical wound are examined. To control the quality of the intervention, a radiography study (OPTG) was performed. The results of the study show that teeth 4.5 and 4.7 were completely removed, there were no cavities or voids at the location of the tooth roots. The boundaries of the cuts are clearly defined.

After surgery it is recommended: antibacterial therapy - 7-10 days; local use of antiseptics, for example, a solution of chlorhexidine 0.05% or furacilin; physical rest for 7-10 days.

When examining Patient G. on the 14th day after surgery, the face is symmetrical, there are no hematomas, bruises, or drainages. Nasal breathing is not impaired. The mouth is opened fully. The sutures in the area of the intervention are mostly intact; locally there is swelling of soft tissues - within normal limits. The edges of the wound are covered with fibrin film. Complaints: discomfort from stitches. There are no other complaints. A decision was made to remove the remaining sutures.

Clinical case 3 with the use of a multilayer autogenous fibrin membrane as part of a tooth extraction operation in an aesthetically significant area (smile area - frontal region).

Patient V. came to the clinic with complaints of discomfort and pain in the frontal part of the upper jaw in the area of 1.1 tooth, previously undergone therapeutic (and orthopedic treatment. On examination: in the area of the central incisor 1.1. signs of a chronic inflammatory process, 2.1. dental unit with orthopedic restoration. In the area of 1.4, 1.5, 1.6 and 2.6 teeth, dental implants with orthopedic restorations are installed; 3.6 and 4.6 dental units are missing, replaced by bridge-like structures supported by adjacent teeth. Somatically healthy.

Diagnosis: K08.1 Secondary partial adentia. K06.84 Partial ridge atrophy. K04.5 Chronic apical periodontitis. Based on the results of the examination and radiography (CBCT and OPTG), it was proposed to remove the orthopedic structure and remove the 1.1 tooth socket with preservation. Subsequently, dental implantation and prosthetics on implants will be performed.

Operation protocol: Before the operation begins, pain relief is performed using local anesthesia and the orthopedic restoration is removed from 1.1. and 1.2 teeth. Next, the circular ligament of the tooth and adjacent soft tissues are separated from the residual root portion of the tooth.

For the purpose of atraumatic removal, the tooth is divided into parts using an ultrasonic instrument, and its fragments are subsequently extracted using thin surgical forceps. After all parts of the tooth are extracted, the socket is inspected. Remains of filling material that extend beyond the tooth root are removed. After a thorough inspection and removal of pathological tissues, it is subjected to antiseptic treatment.

Next, the operator begins to create a multilayer L-PRF membrane from previously taken venous blood, in a volume of 30 ml, which will be used to fill the socket of the extracted tooth on top of the bone graft.

The fibrin clot obtained during the centrifugation process and separated from the red blood cell mass is placed on a flat surface and delicately squeezed out of excess exudate by placing it under a press, for example, using a Pritchard dissolver. Then, linear perforations are created in the resulting single-layer membrane with a scalpel, and the membrane is impregnated with liquid fibrinogen. The prepared membrane is folded into an envelope and excess exudate is squeezed out. Next, the socket is preserved with any osteoplastic material - the choice depends on the doctor’s preferences. The resulting multilayer (two layers) membrane is placed in the socket of the extracted tooth on top of the bone graft, as a finishing material, to ensure isolation of the bone graft from the effects of oral environmental factors, as well as for better wound healing in an aesthetically significant area and preserving the natural gingival contour. Upon completion of the operation, the wound is not sutured. A temporary orthopedic restoration is installed on tooth 2.1, with an imitation of the coronal part of the tooth included instead of unit 1.1, including cable fixation to 1.2.

Post-operative observation: 30 minutes after surgery, the oral cavity and surgical area are examined. To control the quality of the intervention, a radiography study (OPTG) was performed. The results of the study show that tooth 1.1 was completely removed, there were no cavities or voids at the location of the tooth root.

After surgery it is recommended: antibacterial therapy - 7-10 days; local use of antiseptics, for example, a solution of chlorhexidine 0.05% or furacilin; physical rest for the first 3 days. Gentle diet - exclude solid foods, whole vegetables, fruits; click, gnaw nuts, seeds. Avoid placing heavy loads on the anterior (front) teeth.

When examining Patient B. on the 10th day after surgery, her face was symmetrical, there were no hematomas, bruises, or drainages. Nasal breathing is not impaired. The mouth is opened fully, there is no local swelling of the soft tissues. The gingival contour has no signs of an inflammatory process. No complaints.

Clinical case 4 using a multilayer autogenous fibrin membrane as part of an operation to install a dental implant and replenish bone deficiency.

Patient O. came to the clinic with complaints about the long-term absence of a 4.6 tooth in the distal part of the lower jaw.

On examination: 1.1, 1.2, 1.4, 2.1 dental units are missing. In the area of 2.3, 2.4, 2.5 teeth, dental implants are installed. Extended bridge with support on 1.3 and 2.2. Large size restorations for 1.5, 1.6, 2.6, 2.7, 3.6, 3.7 and 4.7. Signs of a chronic inflammatory process in areas 1.5 and 1.6. The third molars in all segments are in a state of dystopia, retention and semi-retention. Somatically healthy.

Diagnosis: K08.1 Secondary partial adentia. K06.84 Partial ridge atrophy. K04.5 Chronic apical periodontitis. Based on the results of the examination and radiography (CBCT and OPTG), it was proposed to carry out dental implantation and subsequent implant-supported prosthetics at the first stage of complex dental rehabilitation.

Surgery protocol: before the operation, anesthesia is performed using local anesthesia. A soft tissue incision is made along the crest of the alveolar process, releasing vertical incisions in the area of 4.5 and 4.7 teeth and subsequent vestibular displacement of a full-thickness mucoperiosteal flap. Then, following the protocol for installing a dental implant, a bed for the implant is formed and installed. To control angulation and assess the correct position of the implant, a healing abutment is temporarily installed. After this, the former is replaced with a plug, which closes the implant shaft. In the process of forming the bed for the implant, autologous bone chips were collected from the cutters used.

Next, the operator begins to create a multilayer autogenous L-PRF membrane from previously taken venous blood in a volume of 80 ml. The fibrin clot obtained during the centrifugation process and separated from the red blood cell mass is placed on a flat surface and delicately squeezed out of excess exudate by placing it under a press, for example, using a Pritchard dissolver. Then, linear perforations are created in the resulting single-layer membrane with a scalpel, and the membrane is impregnated with liquid fibrinogen. The prepared membrane is folded into 2 layers (envelope) and excess exudate is squeezed out using a Pritchard rasp.

The collected autoshavings are mixed with the patient’s blood plasma and, by pressing, are formed into a single, solid graft block. The bone graft is placed on the vestibular side of the alveolar process, along the ridge completely covering and replenishing the existing deficiency of bone tissue in the area of the implant and its plug. A formed multilayer (2 layers) automembrane is placed on top of the bone graft. The vestibular displaced full-thickness mucoperiosteal flap is placed in place, and the wound is sutured with regular and/or H-shaped sutures, the vestibular edge is fixed with absorbable suture material, for example, “Catgut”, diameter 5/0.

Postoperative observation: 30 minutes after surgery, the oral cavity and the area of the surgical wound are examined. To control the quality of the intervention, a radiography study (OPTG) was performed. The results of the study show that the angulation of the implant and its position in the jaw bone fully comply with the anatomical and functional requirements. There are no cavities or voids at the location of the dental implant.

After surgery it is recommended: antibacterial therapy - 7-10 days; local use of antiseptics, for example, a solution of chlorhexidine 0.05% or furacilin; physical rest for the first 7-10 days.

When examining Patient O. on the 14th day after surgery, the face is symmetrical, there are no hematomas, bruises, or drainages. Nasal breathing is not impaired. The mouth is opened fully. The sutures in the area of the intervention are partially intact; locally there is slight swelling. The edges of the wound are covered with fibrin film. Complaints: discomfort from stitches. There are no other complaints. A decision was made to remove the remaining sutures.

When examining Patient O. on day 21: the face is symmetrical, there are no hematomas, bruises, drainages, or soft tissue swelling. Nasal breathing is not impaired. The mouth is opened fully. In the operated area, complete healing of the wound surface is noted. No complaints.

Clinical case 5 with the use of a multilayer autogenous fibrin membrane as part of an operation to form a gingival cuff in the area of the installed implant.

Patient N. came to the clinic with complaints of long-term absence of teeth in the distal parts of the upper (1st segment) and lower (3rd segment) jaw. At the time of treatment during examination: 1.2, 1.4, 1.6 dental units are missing; orthopedic restorations were installed based on dental units 1.3 and 1.5, 2.1 and 2.2; replacement of a defect in a dental unit 2.6 with a large filling material; dental units 3.6 and 3.7 - absent; Light-curing composite restorations were installed on dental units of 4 segments - 4.3, 4.4, 4.5, 4.6, 4.7. Somatically healthy.

Diagnosis: K08.1 Secondary partial adentia. K06.84 Partial ridge atrophy. K08.2 Atrophy of the edentulous alveolar margin. Based on the results of the examination and radiography (CBCT and OPTG), it was proposed to carry out a simultaneous removal of tooth 4.8 and dental implantation in the area of the 3.6 tooth, as well as subsequent (delayed) implant-supported prosthetics, and, to eliminate the deficit in tissue volume, soft tissue plastic surgery in the area of the implant. The second stage is to begin dental rehabilitation using dental implants in 1 segment, including bone and gum grafting. Composite and orthopedic restorations on 1.1, 1.2, 1.3, 1.4, 1.5, 2.1, 2.2, 2.6, 3.5, 4.3, 4.4, 4.5, 4.6, 4.7 - due to wear and violation of marginal fit - are recommended to be replaced.

12 weeks after installing a dental implant in the area of the 3.6 tooth, open the implant, determine the stability coefficient of the dental implant (ISQ) and perform surgery to fill the soft tissue deficiency in this area.

Surgery protocol: before the operation, anesthesia is performed using local anesthesia. Along the crest of the alveolar process, the following are made: a horizontal incision and releasing vertical incisions on the vestibular and oral sides and subsequent displacement of a full-thickness mucoperiosteal flap. Using ceramic and/or diamond burs, bone tissue is separated to open access to the implant, the cover screw is removed, and the stability coefficient of the installed implant is assessed. Then the gum former is tried on.

Next, the operator begins to create a multilayer autogenous L-PRF membrane from previously taken venous blood in a volume of 90 ml, which will be used to increase the volume of soft tissue in the implant area. The fibrin clot obtained during the centrifugation process and separated from the red blood cell mass is placed on a flat surface and delicately squeezed out of excess exudate by placing it under a press, for example, using a Pritchard dissolver. Then, linear perforations are created in the resulting single-layer membrane with a scalpel, and the membrane is impregnated with liquid fibrinogen. The prepared membrane is folded into 2 layers (envelope) and excess exudate is squeezed out. A hole is formed in the center of the resulting multilayer (two layers) autogenous fibrin membrane using a scalpel or mucotome. Then, the automembrane is placed in the wound area, its edges are set under the mucoperiosteal flap, and the gum former is installed in the implant. The use of an automembrane makes it possible to solve the clinical problem of replenishing soft tissue deficits, stabilizing the shape and contour of visible soft tissues in the area of the installed implant, ensuring long-term and stable clinical results. At the end of the operation, the wound is sutured with regular and/or H-shaped sutures and absorbable suture material, for example, Catgut material, diameter 5/0.

Postoperative observation: 30 minutes after surgery, the oral cavity and the closed surgical wound are examined. To control the quality of the intervention, a radiography study (OPTG) was performed. The results of the study show that in the area of the installed implant there are no signs of bone destruction, cavities or emptiness, bone and soft tissue parameters are normal, and the condition is satisfactory.

After surgery it is recommended: antibacterial therapy - 7-10 days; local use of antiseptics, for example, a solution of chlorhexidine 0.05% or furacilin; physical rest 7-10 days; exclude hot, sour, spicy, hot and cold foods.

When examining Patient N. on the 14th day after surgery, her face was symmetrical, there were no hematomas, bruises, or drainages. The mouth is opened fully. The sutures in the area of the intervention are partially intact; locally there is slight swelling. The edges of the wound are covered with fibrin film. Complaints: discomfort from stitches. There are no other complaints. A decision was made to remove the remaining sutures.

When examining Patient N. on day 21: the face is symmetrical, there are no hematomas, bruises, drainages, or soft tissue swelling. The mouth is opened fully. In the operated area, complete healing of the wound surface is noted. No complaints.

Clinical case 6 with the use of a multilayer autogenous fibrin membrane as part of an operation to form a gingival cuff in the area of installed implants.

Patient F. came to the clinic with complaints of prolonged absence of teeth in various parts of the upper (1st and 2nd segments) and lower (3rd and 4th segments) jaw. At the time of treatment during examination: 1.4, 1.5, 1.6 and 1.7 dental units are missing; orthopedic restorations are installed with support on 1.3 dental units; 2.1 - composite restoration installed, 2.4, 2.6, 2.7, 3.6, 3.7 and 4.6 teeth missing, 4.7 - composite restoration installed. Somatically healthy.

Diagnosis: K08.1 Secondary partial adentia. K06.84 Partial ridge atrophy. K08.2 Atrophy of the edentulous alveolar margin. Based on the results of the examination and radiography (CBCT and OPTG), it was proposed to simultaneously carry out dental implantation in all segments in the area of missing 1.4 and 1.6, 2.6 and 2.7, 3.6 and 3.7 dental units. Subsequent (delayed) implant-supported prosthetics are recommended, including, to eliminate the deficit in tissue volume, soft tissue plastic surgery in the area of installed implants.

12 weeks after the installation of dental implants, open the implant, determine the stability coefficient of the dental implant (ISQ), and perform surgery to fill the soft tissue deficiency in the area.

Operation protocol: before the operation begins, pain relief is performed in 1 segment using local anesthesia. Along the crest of the alveolar process, the following are made: a horizontal incision and releasing vertical incisions on the vestibular and oral sides and subsequent displacement of a full-thickness mucoperiosteal flap. Using ceramic and/or diamond burs, bone tissue is separated to open access to the implants, cover screws are removed, and the stability coefficient of the installed implants is assessed.

Next, the operator begins to create a multilayer autogenous L-PRF membrane from previously taken venous blood in a volume of 200 ml, which will be used to increase the volume of soft tissues in the implant area, stabilizing the shape and contour of adjacent tissues. The fibrin clot obtained during the centrifugation process and separated from the red blood cell mass is placed on a flat surface and carefully squeezed out of excess exudate by placing it under a press, for example, using a Pritchard dissolver. Then, linear perforations are created in the resulting single-layer membrane with a scalpel, and the membrane is impregnated with liquid fibrinogen. Next, a second layer of similarly prepared membrane is placed on top, after which the membrane is folded into 2 layers (envelope) and the excess exudate is squeezed out. In the center of the resulting multilayer (four layers) automembrane, using a scalpel or mucotome, a hole is formed for the base of the former.

Then the next automembrane is prepared in a similar way. Two prepared single-layer membranes are laid on top of each other and then the membranes are folded into an envelope, the excess exudate is squeezed out again. Thus, a four-layer automembrane is obtained, ready for immediate use. In a similar way, using a scalpel and/or mucotome, a hole is made in the center of the multilayer automembrane for the base of the former. Due to their specific shape (cylindrical shape with a flat base), ready-made automembranes are threaded onto gum formers.

The use of an automembrane makes it possible to solve the clinical problem of replenishing soft tissue deficits, stabilizing the shape and contour of visible soft tissues in the area of the installed implant, ensuring long-term stable clinical results. Next, gum formers are installed into the implants. The edges of the automembrane are placed under the mucoperiosteal flap.

At the end of the operation, the wound is sutured with regular and/or H-shaped sutures, the vestibular edge of the wound is fixed to the palatal edge with absorbable suture material, for example, Catgut material, diameter 5/0.

Postoperative observation: 30 minutes after surgery, the oral cavity and the closed surgical wound are examined. To control the quality of the intervention, a radiography study (OPTG) was performed. The results of the study show that in the area of the installed implant, bone and soft tissue parameters are normal and the condition is satisfactory.

After surgery it is recommended: antibacterial therapy - 7-10 days; local use of antiseptics, for example, a solution of chlorhexidine 0.05% or furacilin; exclude physical activity for 7-10 days; exclude hot, sour, spicy, hot and cold foods.

When examining Patient F. on the 14th day after surgery, her face was symmetrical, there were no hematomas, bruises, or drainages. The mouth is opened fully. The sutures in the area of the intervention are partially intact; locally there is slight swelling. The edges of the wound are covered with fibrin film. Complaints about discomfort from the stitches, no other complaints. A decision was made to remove the remaining sutures.

When examining Patient F. on day 21: the face is symmetrical, there are no hematomas, bruises, drainages, or soft tissue swelling. The mouth is opened fully. In the operated area, complete healing of the wound surface is noted. No complaints.

Clinical case 7 using a multilayer autogenous fibrin membrane to close a donor wound on the palate as part of a vestibuloplasty operation.

Patient K. came to the clinic with complaints of a long-term absence of teeth in the distal part of the upper (2nd segment) and lower (3rd and 4th segments) jaw. At the time of treatment during examination: 2.3, 2.4, 2.5, 2.6, 3.4, 4.3, 4.5 dental units are missing; orthopedic restorations are installed in areas 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 2.1, 2.2, 2.6, 2.7, 3.3 - 3.5, 3.7; 4.3, 4.4, 4.5, 4.6, 4.7 dental units. 2.6 and 4.3 units are replaced by dental implants with orthopedic structures. Somatically healthy.

Diagnosis: K08.1 Secondary partial adentia. K06.84 Partial ridge atrophy. K08.2 Atrophy of the edentulous alveolar margin. Based on the results of the examination and radiography (CBCT and OPTG), it was proposed to carry out dental implantation in the area of missing 2.3, 2.4, 2.5 teeth and subsequent (delayed) implant-supported prosthetics, including soft tissue plastic surgery to eliminate the deficit in tissue volume in this area.

The second stage is to begin dental rehabilitation using dental implants in the 4th segment in the area of 4.3, 4.4, 4.5 dental units, including bone and gum grafting. It is recommended to replace composite and orthopedic restorations with wear and poor marginal seal.

12 weeks after the installation of dental implants in the area of 2.3, 2.4, 2.5 teeth, open the implants and install gum formers.

After 3 weeks, perform an operation to increase the depth of the vestibule in this area of 2.4, 2.5 and 2.6 dental units using a free gingival graft (GTG) and its external fixation.

Surgical protocol: before the operation, the recipient area is numbed using regional anesthesia. At the border of keratinized and non-keratinized gums on the vestibular side, an incision is made in the mucous and submucosal layers and a flap is formed for apical displacement to the required height of the vestibule recess and the size of the required free gingival graft is determined.

Then, in the donor area (palate), the boundaries of the future transplant are determined and markings are applied. During the period of manipulation in the donor area, the wound in the recipient area is closed with a gauze swab soaked in furatsilin. Next, the operator begins the process of creating a multilayer autogenous L-PRF membrane from a previously collected venous blood in a volume of 180 ml, which will be used to close the donor wound on the palate after collecting the SDT flap. The fibrin clot obtained during centrifugation and separated from the red blood cell mass is placed on a flat surface.

After this, using local anesthesia in the donor area, a narrow strip of SDT flap is taken from soft tissues from the hard palate, within the fat layer. Cutting out the SDT is done with a scalpel along previously specified boundaries. After the flap is removed, the wound in this donor area must be closed.

Next, on a flat surface that has undergone sanitary treatment, the prepared fibrin clot is delicately squeezed out of excess exudate using a Pritchard rasp. Then, linear perforations are created in the resulting single-layer membrane with a scalpel, and the membranes are impregnated with liquid fibrinogen. The first prepared membrane is folded longitudinally into 2 layers and, using a Pritchard rasp, excess exudate is squeezed out and the layers fit as tightly as possible. The second single-layer prepared membrane is folded longitudinally into 3 layers and squeezed out in a similar way. After this, the first two-layer membrane is laid on top of the second, three-layer automembrane, having previously been soaked with liquid fibrinogen. Then, also using a rasp, the multilayer (5 layers) automembrane is squeezed out.

Next, by comparison with the SDT flap obtained from the donor area, the excess length of the membrane is cut off with surgical scissors. After which, the finished multilayer (five layers) automembrane is placed in the wound area. After gluing the donor area with the automembrane, the wound is sutured with a continuous compression suture, absorbable suture material, for example, Russian-made Catgut, 4/0. The operation in the donor area is completed. The subsequent continuation of surgical intervention in the recipient area is excluded from this protocol since it does not provide objective direct and/or indirect information for the disclosure of the topic.

Postoperative observation: 30 minutes after the completion of the entire surgical process, the oral cavity and closed surgical wounds in the donor and recipient areas are examined. To control the quality of the intervention, a radiography study (OPTG) was performed. Further, 1.5 hours after the operation, inspection, monitoring and control are also carried out for delayed bleeding in the operated area. Additionally, in order to prevent the occurrence of bleeding due to the patient’s unconscious injury to the surgical wound in the donor area, a protective mouthguard for the palate, made using a vacuum former, was used.

After surgery it is recommended: antibacterial therapy for 7-10 days; local use of antiseptics, for example, a solution of chlorhexidine 0.05% or furacilin; physiotherapy using ozone; physical rest for 7-10 days; exclude hot, sour, spicy, hot and cold foods.

When examining Patient K. on the 1st day after surgery, the face is symmetrical, there are no hematomas, bruises, or drainages. The mouth is not opened fully. The sutures in the area of the intervention are intact; locally there is slight swelling - within normal limits. The edges of the wound are covered with fibrin film. Complaints: discomfort from stitches. There are no other complaints.

When examining Patient K. on the 7th day after surgery, the face is symmetrical, there are no hematomas, bruises, or drainages. The mouth is opened fully. The sutures in the area of the intervention are partially intact; locally there is slight swelling. The edges of the wound are covered with fibrin film. Complaints: discomfort from stitches. There are no other complaints. A decision was made to remove the remaining sutures.

When examining Patient K. 1 month after the operation, the face is symmetrical, there are no hematomas, bruises, or drainages. The mouth is opened fully. There are no stitches in the area of the intervention. In the area of the donor wound, complete healing of the wound surface is noted. No complaints.

Clinical case 8 using a multilayer autogenous fibrin membrane as part of a closed sinus lift operation and installation of dental implants.

Patient L. came to the clinic with complaints of the long-term absence of several teeth in the distal upper jaw.

On examination: 1.4, 1.7, 2.4, 2.5, 2.6, 2.7, 2.8 and 3.7 dental units are missing. Extended bridges in the area of 1.3, 1.4, 1.5, 1.6 with support on 1.3 and 1.6; in the area of 4.5, 4.6, 4.7, 4.8 with support from 4.5 and 4.8. On the 2.3 tooth unit there is a composite restoration. Large restorations on dental units 3.5, 3.6, 3.7, 3.8. Signs of chronic inflammation in the area - 1.3, 1.4, 1.5, 1.6 and 4.5 dental units. Somatically healthy.

Diagnosis: K08.1 Secondary partial adentia. K06.84 Partial ridge atrophy. K04.5 Chronic apical periodontitis. Based on the results of the examination and radiography (CBCT and OPTG), it was proposed to carry out comprehensive dental rehabilitation. At the first stage, carry out dental implantation with raising the bottom of the maxillary sinus (closed sinus lift) and subsequent prosthetics supported by implants in the area of 2.4 - 2.7 dental units.

Surgery protocol: before the operation, anesthesia is performed using local anesthesia. Using a navigation template for implantation, a medical marker indicates the location of the implants. Along the crest of the alveolar process, a soft tissue incision is made (exposing the alveolar crest) from 2.4 to 2.7 dental units. Vertical releasing incisions are made on the vestibular side medial to 2.4 and distal to 2.7 teeth. Then, following the protocol for installing dental implants, the bed is formed step by step and the implants are installed one by one.

In the area of 2.5 dental units, CBCT results summarized the deficit of bone tissue in height. To raise the floor of the maxillary sinus, a mucot is used. To control angulation and assess the correct position of the installed implants, healing abutments are temporarily installed. Further, in the area of 2.6 dental units, an increase in the height of the alveolar ridge is also necessary. Due to the specific anatomical features, raising the floor of the maxillary sinus in this area requires preventive measures to prevent the onset of intraoperative complications and the development of delayed complications.

To this end, the operator begins to create a multilayer autogenous L-PRF membrane from previously taken venous blood in a volume of 180 ml. The fibrin clot obtained during the centrifugation process and separated from the red blood cell mass is placed on a flat surface and delicately squeezed out of excess exudate by placing it under a press, for example, using a Pritchard dissolver. Then, linear perforations are created in the resulting single-layer membrane with a scalpel, and the membrane is impregnated with liquid fibrinogen. The prepared membranes are folded into 3 layers (envelope) and excess exudate is squeezed out, for example, also using a Pritchard rasp.

In the process of forming a bed for the implant in the area of 2.6 dental units, the resulting multilayer automembrane is introduced into the hole and, using a mucotome, manipulations to raise the bottom of the maxillary sinus continue. The introduced automembrane will create soft and uniform pressure, which will separate the bone graft from the mucous Schneiderian membrane and provide improved bone regeneration. After this, a bone graft is introduced into the hole, obtained using cutters to form a bed of 2.4 dental units. The autologous bone shavings are pre-mixed with the patient’s blood plasma and formed into a single, solid graft block by pressing. On top of the bone graft, the formed multilayer (2 layers) automembrane is again introduced into the hole. After which the operation in this area continued in the classical way. In area 2.7 of the dental unit, the dental implant was installed in the same way as in area 2.4. Gum contour formers are installed in all implants to check their position and angulation. After this, the formers are replaced with implantation plugs, which close the implant shafts.

The remaining formed multilayer (2 layers) automembranes are placed on top of the plugs, which will solve the clinical problem of replenishing the soft tissue deficiency in the area of installed implants, ensuring a long-term and stable clinical result. Full-thickness mucoperiosteal flaps are placed in place, and the wound is sutured with regular and/or H-shaped sutures, the vestibular edge is fixed to the palatal edge with absorbable suture material, for example, "Catgut", diameter 5/0.

Postoperative observation: 30 minutes after surgery, the oral cavity and surgical area are examined. To control the quality of the intervention, a radiography study (OPTG) was performed. The results of the study show that the angulation of the implants and their position in the jaw bone fully comply with the anatomical and functional requirements. No complications were identified in the area of sinus floor elevation. There are no cavities or voids at the location of dental implants.

After surgery it is recommended: antibacterial therapy for 7-10 days; treatment of the upper respiratory tract with sprays or drops with a vasoconstrictor effect for improved outflow of secretions from the sinuses; local use of antiseptics, for example, a solution of chlorhexidine 0.05% or furacilin; ban on physical activity for 7-10 days; physiotherapy using ozone.

When examining Patient L. on the 8th day after surgery, the face is symmetrical, there are no hematomas, bruises, or drainages. Nasal breathing is not impaired. The mouth is opened fully. The sutures in the area of the intervention are mostly intact; There is swelling locally - within normal limits. The edges of the wound are covered with fibrin film. Complaints: discomfort from stitches. In the buccal area there are traces of mechanical trauma with suture material. There are no other complaints.

When examining Patient L. on the 17th day after surgery, the face was symmetrical, there were no hematomas, bruises, or drainages. Nasal breathing is not impaired. The mouth is opened fully. The sutures in the area of the intervention are partially intact; locally there is slight swelling. In the operated area, complete healing of the wound surface is noted. Complaints: discomfort from stitches. There are no other complaints. A decision was made to remove the remaining sutures.

List of cited sources:

1. US 7,604,668 (2009-10-20) Composite self-cohered web materials

2. RU 2367475 (2009-09-20) MEMBRANE FOR USE IN DIRECTED TISSUE REGENERATION

3. Marx R. Platelet - rich plasma: evidence to support its use. J. Oral Maxillofac. Surg. 2004; 62:489-96

4. Ehrenfest D.M.. Bielecki T., Mishra A. et. al. In search of a consensus terminology in the field of platelet concentrates for surgical use: platelet-rich plasma (PRP). platelet-rich fibrin (PRF), fibrin gel polymerization and leukocytes. Curr Pharm Biotechnol. 2012: 13(7): 1131-7.

5. Aroca S., Keglevich T., Barbieri B. et al. Clinical evaluation of a modified coronally advanced flap alone or in combination with a platelet-rich fibrin membrane for the treatment of adjacent multiple gingival recessions: a 6-month study. J Periodontol. 2009: 80(2):244-52.

6. Corteilini S., Castro A., Temmerman A. et al. L-PRF block for bone augmentation procedure: a proof-of-concept study. J Clin Periodontol. 2018;

7. Castro A., Meschi N., Temmerman A. et al. Regenerative potential of leucocyte- and platelet-rich fibrin. Part B: sinus floor elevation, alveolar ridge preservation and implant therapy. A systematic review. J Clin Periodontol. 2017: 44(2):225-34.

8. Ehrenfest D.M., Andia I., Zumstein M.A. 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. Muscle, Ligaments and Tendons Journal 2014: 4(1): 3-9.

9. Schar M., Diaz-Romero J., Kohl S. et al. Platelet-rich concentrates differentially release growth factors and induce cell migration in vitro. Clin Orthop Relat Res. 2015: 473: 1635-430.

10. Marenzi G., Riccitiello F., Tia M. et al. Influence of Leukocyte- and Platelet-Rich Fibrin (L-PRF) in the Healing of Simple Postextraction Sockets: A Split-Mouth Study. BioMed Research International 2015; 1-6. http://dx.doi.org/10.1155/2015/369273.

11. Fujioka-Kobayashi M., Miron R., Hernandez M. et al. Optimized Platelet-Rich Fibrin With the Low-Speed Concept: Growth Factor Release, Biocompatibility and Cellular Response. Journal of Periodontology 2016; DOI:10.1902/jop.2016.160443

12. Nelson R. Pinto, Andy Temmerman, Ana B. Castro, Simone Cortellini, Wim Teughels, Marc Quirynen. Guidelines for the use of L-PRF. https.//apdental.gr/wp-content/uploads/2020/05/S-INTRASPIN-STEP-BY-STEP-1.pdf

Claims (11)

1. A method for manufacturing a multilayer autogenous fibrin membrane, according to which blood is taken from the patient’s ulnar vein, then an autogenous fibrin clot is obtained from the obtained blood by centrifugation, after which the clot is squeezed out to obtain an autogenous fibrin membrane, then the autogenous fibrin membrane is impregnated with liquid fibrinogen, having previously carried out linear perforations of its surface, then a multilayer autogenous fibrin membrane is formed from the autogenous fibrin membrane. 2. The manufacturing method according to claim 1, characterized in that an autogenous fibrin membrane is obtained by squeezing out the exudate. 3. Manufacturing method according to claim 1, characterized in that the exudate is squeezed out using a Pritchard dissolver. 4. Manufacturing method according to claim 1, characterized in that the exudate is squeezed out using a press. 5. The manufacturing method according to claim 1, characterized in that a multilayer structure of an autogenous fibrin membrane is formed by folding it. 6. The manufacturing method according to claim 5, characterized in that the flat part of the multilayer autogenous fibrin membrane is squeezed out after each folding. 7. The manufacturing method according to claim 5, characterized in that the multilayer autogenous fibrin membrane is impregnated with liquid fibrinogen before each folding. 8. The manufacturing method according to claim 1, characterized in that a multilayer structure of an autogenous fibrin membrane is formed by stacking autogenous fibrin membranes on top of each other. 9. The manufacturing method according to claim 8, characterized in that each subsequent autogenous fibrin membrane is compressed with the previous ones. 10. The manufacturing method according to claim 1, characterized in that the autogenous fibrin clot obtained by centrifugation is placed on a sanitized flat surface. 11. The manufacturing method according to claim 1, characterized in that blood is taken from the patient’s ulnar vein in a volume of 30 to 200 ml.