Dr. Dong-Seok Sohn demonstrates guided bone regeneration (GBR) using a concentrated growth factor (CGF) membrane.

 

Guided bone generation (GBR) is one of popular method to augment bone defect associated with implant placement. Resorbable or non-resorbable membrane is required to exclude soft tissue ingrowth into the bone graft for successful GBR. Variable platelet concentrates have been introduced to accelerate new bone formation. Recently autologous fibrin rich block with concentrated growth factors (CGF) was introduced by Dr. Sacco in 2006. CGF doesn’t require any chemical or allergenic additives, such as bovine thrombin or anticoagulants unlike PRP and PRGF, so it is free from viral transmission disease. CGF barrier can be used as alternatives to resorbable membrane in GBR and bone graft in sinus augmentation, and it accelerates new bone formation. This case report demonstrates the application of CGF barrier for GBR to accelerate new bone formation.

 Figure 1: Special centrifuge for the preparation of CGF (Medifuge, Silfradent srl, Sofia, Italy), one step protocol is needed to obtain CGF from patient’s venous blood sample.

 

Figure 2: Concentrated growth factors are aggregated in the middle layer after 12 minutes centrifugation using variable speed. Red corpuscles of lower layer is separated from fibrin clot with scissor before use

 

 

 Figure 3: 65 year old woman visited our department to replace the missing #18and #19 with implant supported prosthesis. Cortical perforation was done before implant placement. Two Implants (Legacy implant, Implant Direct LLC, USA) were placed. Note dehiscence defect around implant.

 Figure 4: 6 pieces of GCF were prepared from the patient's blood with the Medifuge machine.

 Figure 5: 3 pieces of dense CGF barrier were prepared by compression of CGF fibrin block. 

 Figure 6: Allograft (Orthoblast II®, IsoTis Orthobiologics, Irvine, CA and Allotis®, Bio-Tis, Korea) was mixed with CGF. Gel conditioned bone graft was gained.

 Figure 7: The mixture of allograft and CGF was grafted to augment the thin alveolar ridge. Thanks to gel conditioned bone graft, bone graft maintained the shape. This was beneficial for space maintenance.

  Figure 8: Three pieces of CGF barrier were covered on the bone graft to exclude soft tissue ingrowth into the bone graft and to accelerate new bone formation and soft tissue healing. 

 Figure 9: After only 12 weeks healing, implants were exposed and excellent bone regeneration was gained.

 Figure 10: Final restorations after 2 months of loading.

 Figure 11: Radiograph at 2 months loading.

Compressed CGF can be used barrier membrane with growth factors as alternative collagen membrane. This barrier induces faster formation and soft tissue healing. When it is mixed with bone graft, faster bone formation can be obtained as seen in this case report. When CGF is applied to donor site of connective tissue graft, it reduces pain and inflammation and bleeding tendency. In addition, faster soft tissue healing can be obtained. CGF can be applied for sinus augmentation to induce faster new bone formation too.