The gold standard of bone augmentation for dental implants in severe alveolar bone atrophy is autogenous bone graft, but it has disadvantages such as limited amounts of grafted bone, poor morphological and aesthetic outcomes, and donor-site morbidity and invasiveness, especially in cases with diseases. In this reported case, the authors applied a novel tissue engineering method as minimally invasive surgery for a 58-year-old patient who had severe bone atrophy. The method, tissue-engineered bone (TEB), composed of mesenchymal stem cells as stem cells, platelet-rich plasma as growth factor and guided bone regeneration membrane. After bone regeneration by TEB, three 13 mm long dental implants were inserted. Adequate bone regeneration was shown by radiological analysis and histological observation. The augmented bone height was 4.2 mm after the operation and the radiopaque areas were increased. The clinical progress over 2 years showed a good course without bone resorption. These results indicated that TEB, as bone regeneration treatment with minimal invasiveness, could be useful as one of the novel options in dental implant treatment with severe bone atrophy.
Autogenous bone grafts remain the gold standard of bone augmentation for dental implants in severe alveolar bone atrophy cases, but grafted bone supplies are limited, there is difficulty in shaping the graft, and donor-site morbidity and a heavy patient burden can occur, especially in cases with diseases. Tissue engineering is a new minimally invasive method to restore and reconstruct tissues or organs, which involves the morphogenesis of new tissue using constructs formed by isolated cells, growth factors and scaffolds.
Mesenchymal stem cells (MSCs) extracted from various tissues, including bone marrow, adipose, muscle, dermis, neural tissue and dental pulp, have the ability to self-renew and transdifferentiation potential, and can also be applied for bone regeneration in oral and maxillofacial surgery fields. Platelet-rich plasma (PRP), collected by centrifugation of autologous peripheral blood, has been reported to enhance bone regeneration or promote soft and hard tissue healing. PRP includes growth factors such as platelet-derived growth factor (PDGF), transforming growth factor beta (TGF-β), vascular endothelial growth factor (VEGF) and epithelial growth factor (EGF). These growth factors are released by the degranulation of platelets. PRP also has several advantages over the use of animal sera or recombinant growth factors from potentially safe and effective clinical applications.
The authors have tried to apply the method as bone augmentation for dental implant treatment, such as sinus floor elevation. In the present case, they applied this tissue engineering technique for dental implant treatment with guided bone regeneration (GBR) membrane for a patient who had severe bone atrophy. The patient’s course was clinically and radiographically followed for 2 years.
A 58-year-old female patient who had lost her first and second molar teeth suffered from an atrophied mandibular alveolar crest ( Fig. 1 ). There were severe bone defects in her mandible bone and her left mandibular second premolar suffered from tooth fracture. The mandible had been absorbed vertically and horizontally, and bone ridge augmentation was required for implant placement. The patient was in good general health and free from any disease that may have influenced the treatment outcome (e.g. diabetes, immunosuppressive chemotherapy, rheumatoid arthritis). Since the patient did not agree to an iliac bone graft, a novel minimally invasive bone regeneration method was used. The patient was given extensive information about the procedures, including the surgery, graft material, implants and the uncertainties of using a new bone-regenerative method. The research protocol was approved by the university ethics committee. The patient agreed to this approach and chose dental implant treatment bone regeneration using the tissue engineered bone (TEB) method.