Modern dentistry focuses on preserving teeth and providing a healthy dentition with optimal functional efficiency, structural balance, and, aesthetic harmony. Contemporary dentistry today offers two solutions to address the problem of partial edentulousness which include:

1. Removable partial dentures and

2. Fixed partial dentures. 

3. The third modality of tooth replacement, the “Dental Implant” was brought into existence.

We need to know that immediately after the tooth extraction, a waiting period of 6 to 12 months is required to permit bone regeneration to fill the bony socket. This prolongs treatment time and permits bone resorption to occur. ⁽¹⁾

Most of the dimensional changes occur in the first 3 months of socket healing and cause ridge contractions. To counteract contraction of the residual ridge, different strategies have been tested, most of them have involved a combination:

1. Socket Preservation including different grafting materials

2. Immediate implantation and the use of different grafting materials. 

To promote tissue healing and minimize bone loss during the healing period, materials have been used including autografts and allografts successfully but the disadvantage is a second surgical site in the case of autografts and the risk of disease transmission in the case of allografts has limited their use.

Xenogenic demineralized bone matrix can induce new bone formation, a combination of xenogenic demineralized bone with calcium sulfate hemihydrate also provides better moldability for proper packing in the socket.

Also, a combination of mixing of bone material mixed with platelet aggregates has been brought into the field to hasten tissue repair and regeneration. ⁽²⁾

Looking into the idea that the defect can be augmented using grafting material either from the patient's own body or external sources. The effectiveness of bone graft materials can be improved with various commercially available materials or autogenous options.

Among many materials, Fibrin glue emerged as a promising adjunct that meets the properties of sealant, and hemostatic properties and also as a scaffold for new bone formation which helps in minimizing spaces between bony particles, fastening revascularisation, thereby improving bone graft integration and remodeling.

This concept gave a new idea towards the development of sticky bone (growth factors rich in bone graft), first introduced by Sohn in 2010. ⁽²⁾

Evolution of sticky bone

1. In 1954, Kingsley designated the term PRP(Platelet-rich plasma) for thrombocyte concentrates in various blood experiments.

2. In 1970, Matras introduced Fibrin glue as the concentration of fibrinogen in donor plasma was low, which led to the stability and quality of it being suboptimal.

3. In 2000, Choukron et al, introduced PRF, because of the strong fibrin gel polymerization present in the preparation of platelet concentrates, the so-called PRF.

4. In 2006, Sacco identified Concentrated Growth Factors, centrifuged at 2400-2700rpm was used to separate cells from the venous blood. The Fibrin blocks obtained were larger, richer, and denser.

5. Everts et al focused more on the leukocyte component in 2008.

6. In 2009, Dohan Ehrenfest et al, explained a classification based on the separation of the products using the fibrin architecture and cellular content.

• Pure platelet-rich plasma (P-PRP)

• Leucocyte- and platelet-rich plasma (L-PRP)

• Pure platelet-rich fibrin (P-PRF), and

• Leucocyte Platelet-rich fibrin (L-PRF) 

7. In 2010, Sohn brought up the concept of sticky bone(a combination of autologous fibrin glue mixed with a bone graft). ⁽¹⁾

The making of sticky bone:

1. We need to collect 20-60CC of venous blood from the patient.

2. Divide the collected blood into two non-coated vacutainers and centrifuge at 2400-2700rpm using a rotor running at alternated and controlled speed.

3. Higher growth factors were obtained if the centrifuge stopped after 2 minutes of centrifugation. The upper layer contains AFG and the bottom layer contains red blood cells. Test tubes are taken out of the centrifuge and AFG is collected with the help of a syringe.

4. The obtained AFG is mixed with particulate bone powder and allowed for 5-10 minutes for polymerization in order to produce sticky bone which is yellow.

5. The sticky bone mixed with autologous thrombin in the RBC layer shows a red color. ⁽¹⁾

Importance of Sticky bone (Autologous fibrin glue and particulate bone graft) in regeneration:

Homologous materials are always considered the gold standard compared to all other materials in the regenerative race. Autologous fibrin glue has proven to be better compared to commercially available ones.

The story of sticky bone is depicted with the combination of autologous fibrin glue and bone particulate graft. Autologous bone is considered supreme due to its properties of osteogenic, osteoinductive, and osteoconductive but the second surgical site preparation for the graft has a lot of disadvantages which limited its availability.

1. Displacement of the graft material during placement

2. Donor site morbidity

3. Increased risk of infection

4. Deformity of the donor site

5. Time and cost of treatment

Additionally, there is a problem of poor viability due to compromised vascularization.

Due to the limitations of autograft bone, the development of allograft and xenograft bone grafts is underway.

The concept of a three-dimensional scaffold has developed which enables cell adhesion to scaffold and promote the ingrowth of bone. The scaffold material should be biocompatible and biodegradable.

Fibrin serves as a natural scaffold, having biocompatible and biodegradable properties, and the initial stability it provides to the graft materials. It promotes cell migration into the site of repair and releases growth factors for a more prolonged period. It acts as a scaffold for bone and cartilage tissue. 

Based on this concept, the sticky bone developed helps in the stabilization of the bone graft in the defect present hence quickening tissue healing thus helping in minimizing bone loss during the healing phase.

The sticky bone along with different growth factors hastens the healing process and is very efficient in the regeneration of lost tissues. It is used in intra-bony defects, bony augmentation, edentulous alveolar ridge defects, immediate implantation procedures, and socket preservation. ⁽¹⁾

MedBound Times has connected with Dr. Lakshmi Sailaja Sistla, BDS, MDS in Periodontology and Implantology to share her opinion about “The application of Sticky Bone in regenerative procedures and how it is to be considered in Periodontics.”

In her words "Healing is the body's natural mechanism for trauma/ surgery. We come across a variety of skin wounds, bone fractures & ligament injuries. Depending on the extent, severity & complexity of the trauma, a plethora of treatment alternatives are available. It is generally known that each of the above-mentioned injuries heals variable with time, some even demand immobilization, and each tissue heals differently.

The periodontium is the tooth-supporting apparatus, which consists of gums, bone & a fibrous connective tissue ( periodontal ligament ). Each of the tissues has a variable healing rate which adds to the complexity of periodontal healing.

Pyorrea/ pyorrhea/ gum disease damages gums & the underlying bone. It is managed both non-surgically and surgically discerned by the severity. The use of various bone grafts is one of the commonly employed methods. Graft particle stability is one very important factor in periodontal healing.

Sticky bone is an amalgamation of bone graft particles with a variety of platelet concentrates. The fibrin network polymerizes to hold graft particles stably & at the same time release a plethora of growth factors over a period of time. This aids in the retention of graft particles, prevention of dislodgement & further promoting better osseous integration of the particles.

Feasibility 

Application of platelet concentrates is beneficial as it is mainly autologous in origin, rich in growth factors ( hence beneficial to jumpstart the natural process of healing ) & cost-effective. There is no need for external preservatives which could trigger allergy.

Limitations 

Limitations are not based on material, as it is autologous. Special care in handling blood and specific instruments is necessary, which may increase initial financial investment."

References:

1. Gurpur, Prakash Pai, Manjunath Gurpur, Anitha Dayakar, Amy Christina, and Mathews. "The Enigma of Sticky Bone." International Journal of Current Advanced Research 8, no. 12 (December 2019): 20741–20743. https://www.researchgate.net/publication/343600098_THE_ENIGMA_OF_STICKY_BONE.

2. Kumar, Rajesh, and Anil Sharma. "Comparative Analysis of Sticky Bone and Demineralized Bone Matrix with Calcium Sulfate Hemihydrate on Alveolar Bone and Soft Tissue Regeneration." Journal of Oral and Maxillofacial Surgery 82, no. 1 (January 2024): 45–52. https://journals.lww.com/joro/fulltext/2024/16010/comparative_analysis_of_sticky_bone_and.4.aspx.       

By Dr. Lakshmi Sahithi Tanneru