Following the extraction of a tooth, dental implants are an excellent option for patients due to their favourable aesthetics and functional capabilities. However, various clinical, biomechanical, and biological conditions must be met for long-term success. Dimensional changes to the alveolar bone start with the loss of bundle bone during the first seven to 14 days after a tooth is extracted. The preservation of bone quality in the alveolar ridge is crucial for maintaining healthy and functional dentition.
The clinician must rely on the best evidence to guide them on the management of the extraction site – the timing of implant placement, as well as the appropriateness of socket augmentation protocols. Where socket augmentation is indicated, many different bio-enhancement techniques now exist to minimise bone loss following an extraction. This field of study is rapidly developing, and the acquisition of knowledge and skills around bio-enhancement techniques in alveolar ridge preservation (ARP) has become an expectation within the competency of the advanced practitioner.
Contemporary ridge preservation techniques
Immediate placement of dental implants into the extraction socket following tooth extraction is a common contemporary solution for preserving the alveolar ridge, with or without simultaneous bone augmentation. However, primary stability and aesthetics may be challenged if bone quality is not sufficient, and immediate placement is not always indicated.
Socket augmentation is recommended to maintain the shape of the alveolar ridge when immediate or early implant placement with sufficient primary stability cannot be achieved. This may be due to significant bone defects, compromised socket walls, or unfavourable conditions of the soft tissue.
In guided bone regeneration (GBR), barrier membranes are implanted over a tissue defect, to protect a bone graft from cell invasion from the gingival epithelium and connective tissue. This technique is widely accepted, but also presents risks, like membrane exposure, wound dehiscence or infection. Non-biodegradable barrier membranes are advantageous for supporting large-scale tissue regeneration, however, they require surgical intervention to remove the membrane.
The use of bone substitute materials (BSM) in oral surgery and implantology has been employed since the 1970s with the use of hydroxyapatite (HA). Contemporary ARP makes use of many bioactive materials, encompassing HA, collagen, and 3D bone repair materials. Biomimetic materials containing hydrogels, stem cells and vascular endothelial cells, for example, can be engineered and printed, promoting enhanced integration and regeneration.
A buccal fat pad (BFP) can be used as a natural barrier to cover non-resorbable devices for vertical ridge augmentation. Using BFP flaps to repair oral defects has proven to be efficient in bone augmentation. The adipose tissue deposits along the anterior border of the masseter muscles can be used for the repair of oral defects, and are a rich and easily accessible source of mesenchymal stem cells.
Autologous platelet concentrates
Platelets are a major source of autogenous growth factors, which were first employed in the 1970s with platelet-rich plasma (PRP), a blood-based therapy which involves injecting concentrated plasma into a site of injury.
Platelet-rich fibrin (PRF), developed in 2001, is a biomaterial derived from a patient's own blood, consisting of a concentrated fibrin matrix containing platelets, white blood cells (leukocytes), and growth factors. PRF acts as a scaffold to promote tissue regeneration and wound healing. Unlike PRP, PRF doesn't require added anticoagulants during preparation. Numerous studies have shown that the use of autogenous PRF platelet concentrates during ARP reduces healing time and improves angiogenesis and bone regeneration. PRF promotes socket sealing by enhancing the fibrin matrix. Additionally, it decreases post-extraction pain and has antibacterial properties, reducing the risk of infection.
Concentrated growth factors (CGF) are the most recent generation of platelet substitutes. Created in 2006, CGF maximises the concentration of growth factors such as vascular endothelial growth factor (VEGF), transforming growth factor-β1 (TGF-β1) and β2 (TGF-β2), fibroblast growth factor (FGF), platelet-derived growth factor (PDGF) and insulin-like growth factor (IGF) present in blood platelets. CGF treatment is promising, and may well be a simple and low-cost solution in the near future, but the evidence is still emerging to confirm its appropriate application.
Evolving protocols
Bio-enhancement and alveolar ridge preservation protocols are evolving in line with advancements in surgical techniques, biomaterials and in the science examining the biological mechanisms behind bone growth. Staying abreast of the evidence to support effective ARP is essential for the advanced dentist.
Eminent specialist oral surgeon, Professor Cemal Ucer, examines these in the Advanced Certificate in Management of Tooth Loss: Immediate Implants vs Socket Preservation course at the ICE Postgraduate Institute and Hospital. The comprehensive course includes lectures, workshops and hands-on experiences with expert practitioners, covering all aspects of tooth loss management, including hands-on practical experience in socket augmentation and alveolar ridge preservation.
Many techniques exist to minimise the loss of bone following the extraction of a tooth. Developing the confidence and critical skills to develop an evidence-based treatment plan as this exciting field of study evolves is an essential requirement for a serious practitioner.
References available on request.
For more information visit www.ucer-clinic.dental