Platelet-Rich Fibrin in Mesh Exposure Repair

INTRODUCTION
Guided bone regeneration in ridge augmentation procedures have gained greater importance in recent years as we demand more esthetic results in the reconstruction of the missing dentition for our patients. Sometimes these ridge augmentation defects are large and require larger amounts of graft material to be used. These situations are commonly handled with block grafts or particulate graft encased in a titanium mesh or, recently, with products containing bone morphogenic proteins (BMPs)^1,2 also commonly called growth factors. The titanium mesh avoids the morbidity of a second surgical site needed in autologous block grafts, and the cost is very reasonable when compared to the products containing growth factors, such as INFUSE (Medtronix). These guided-tissue regeneration procedures require tension-free flap suturing and good primary closure,³ but, even with good mattress suturing techniques and adequate release of the periosteum, the most common complication is flap dehiscence with exposure of the graft. Once the surgical wound opens and the mesh becomes exposed, although it is not a catastrophic problem, this leads to eventual contamination of the graft and partial or complete loss of the material.

Focus on Growth Factors
Growth factors have recently been the focus of much attention in guided-tissue regeneration techniques and, in particular, the use of autologous blood concentrates such as platelet-rich plasma, platelet-rich growth factors, and platelet-rich fibrin (PRF).

The PRF membrane contains large quantities of growth factors.^4,5 Growth factors are synthesized by megakaryocytes and stored mainly in the α granules of platelets. Once the platelets are activated in areas of tissue damage, they secrete proteins such as fibrinogen, fibronectin, and vitronectin, and growth factors including BMPs, transforming growth factor-ß, platelet-derived growth factor, insulin-like growth factor, vascular endothelial growth factor, and fibroblast growth factor,^6,7 and an important coagulation matricellular glycoprotein thrombospondin-1 during 7 days. The fibrin membrane also provides an excellent scaffold for epithelialization, and the high concentration of growth factors and release of cytokines accelerate the process of healing by promoting the formation of microvasculature and the growth of new tissue.^8-10

I have seen accelerated healing results with extraction socket grafting using PRF membranes and, when a recent ridge augmentation procedure using titanium mesh showed a surgical flap dehiscence and an early mesh exposure, it was decided to use a PRF membrane to stimulate soft-tissue closure over the prematurely exposed mesh. This brief article will describe a ridge augmentation procedure in which an early mesh exposure occurred, and will then demonstrate the steps taken to correct the complication.

CASE REPORT
Diagnosis and Treatment Planning
A healthy female in her 30s presented with a large ridge defect in the area of the maxillary right first premolar after the extraction of an infected tooth (Figure 1). Attempting the replacement of the missing premolar with a fixed partial denture or an implant without augmenting the ridge would have resulted in a very long tooth and a cosmetic failure.

A periapical radiograph shows the 2-dimensional view of the extraction site and deficient bone height (Figure 2).

A cone beam computed tomography study was also done for treatment planning purposes. A cross-sectional view showed 5.5 mm bone height to the floor of the maxillary sinus and less than 3.0 mm width of bone at the crest (Figure 3).

Figure 1. Photograph of deficient alveolar ridge.	Figure 2. Radiograph of deficient alveolar ridge.

Clinical Protocol
A graft procedure was conducted by elevating a full-thickness mucoperiosteal flap, creating multiple cortical perforations (Figure 4) to promote regional acceleratory phenomenon.¹¹ A titanium mesh was also used to contain the NovaBone (ACE Surgical) bone putty (Figure 5). The titanium mesh was stabilized with 3 titanium screws (MiniPlate [Impladent]) (Figure 6) and the flap was sutured with individual and mattress Cytoplast Polytetrafluoroethylene (PTFE) sutures (Osteogenics Biomedical) (Figure 7). The postoperative radiograph shows that the graft was well contained within the titanium mesh (Figure 8), stabilized with 3 screws.

One week after the surgery, at the postoperative visit, the wound showed signs of a slight opening of the incision (Figure 9), and in 2 weeks, the surgical site showed a definite exposure of the titanium mesh.

Figure 4. Surgical flap and cortical perforations.	Figure 5. Bone putty in titanium mesh crib.
Figure 6. Titanium mesh stabilized with screws.	Figure 7. Flap sutured.
Figure 8. Post-op radiograph of grafted area.	Figure 9. Early flap dehiscence.
Figure 10. Mesh exposure at 3 weeks.	Figure 11. Platelet-rich fibrin (PRF) repair covering exposed mesh.

Figure 12. Complete mesh coverage after PRF repair.

The patient was asked to continue her chlorhexidine rinses (Peridex [3M ESPE]) twice daily, and weekly follow-up appointments were scheduled. Three weeks after the graft procedure was completed, the mesh exposure continued to increase in size to an exposure of about 5.0 mm, but there were no signs of infection or inflammation (Figure 10).

The patient was informed of the risk of graft failure and agreed to a repair attempt with PRF. The area was anesthetized and the tissue surrounding the exposed mesh was undermined with a scalpel, using sharp dissection to avoid detaching a flap. The PRF membranes were then tucked under the undermined edges and secured with PTFE sutures (Figure 11).

The complete coverage of the exposed titanium mesh 2 weeks after the repair is shown in Figure 12.

CLOSING COMMENTS
The results, although anecdotal, would seem to indicate that the PRF membranes helped the repair by providing a scaffold for re-epithelialization; and the growth factors induced fast tissue growth and healing. The author believes this is one of many applications for the use of PRF in the daily practice of dentistry.

References

1. Marx RE, Carlson ER, Eichstaedt RM, et al. Platelet-rich plasma: growth factor enhancement for bone grafts. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 1998;85:638-646.
2. Slater M, Patava J, Kingham K, et al. Involvement of platelets in stimulating osteogenic activity. J Orthop Res. 1995;13:655-663.
3. Greenstein G, Greenstein B, Cavallaro J, et al. Flap advancement: practical techniques to attain tension-free primary closure. J Periodontol. 2009;80:4-15.
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5. Dohan Ehrenfest DM, de Peppo GM, Doglioli P, et al. Slow release of growth factors and thrombospondin-1 in Choukroun’s platelet-rich fibrin (PRF): a gold standard to achieve for all surgical platelet concentrates technologies. Growth Factors. 2009;27:63-69.
6. Nurden AT, Nurden P, Sánchez M, et al. Platelets and wound healing. Front Biosci. 2008;13:3532-3548.
7. Mehta S, Watson JT. Platelet rich concentrate: basic science and current clinical applications. J Orthop Trauma. 2008;22:433-438.
8. Marx RE, Carlson ER, Eichstaedt RM, et al. Platelet-rich plasma: growth factor enhancement for bone grafts. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 1998;85:638-646.
9. Choukroun J, Diss A, Simonpieri A, et al. Platelet-rich fibrin (PRF): a second-generation platelet concentrate. Part IV: clinical effects on tissue healing. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2006;101:e56-e60.
10. Anitua E, Sánchez M, Nurden AT, et al. Autologous fibrin matrices: a potential source of biological mediators that modulate tendon cell activities. J Biomed Mater Res A. 2006;77:285-293.
11. Misch CE. Contemporary Implant Dentistry. 2nd ed. St Louis, MO: Mosby; 1999:452-464.

Dr. Boudet graduated from the Medical College of Virginia in 1980. He became a commissioned officer for the United States Public Health Service. His tour of duty ended in 1982 and he was asked to serve as dental director of 4 dental clinics for Florida Community Health Centers, receiving an award for outstanding service. Dr. Boudet established his dental practice in West Palm Beach, Fla in 1983 and has been in the same location for 26 years. He is a Diplomate of the International Congress of Oral Implantologists, a member of the Central Palm Beach County Dental Society and a chairman of the advanced crown and bridge section of the Atlantic Coast Dental Research Clinic. Dr. Boudet’s articles on prosthetics and implants have been published in several popular dental journals. He can be reached via e-mail at themouthman@yahoo.com.

Disclosure: Dr. Boudet reports no disclosures.