Optimized bone grafting

MBG/BSA Bone Grafts Immunomodulate Bone Regeneration by Releasing Bioactive Ions in Inflammatory Bone Defects

Since the diseases that cause bone defects are mostly inflammatory diseases, the current bone grafts are unable to effectively regulate osteoimmune activity, leading to the impaired osteogenesis and unfavorable bone regeneration. In this study, inspired by bone composition, biomimetic mesoporous bioactive glass nanoparticle (MBG)/bovine serum albumin (BSA) bone grafts are designed for inflammatory bone defects. Systematically, MBG/BSA bone grafts are evaluated for characterization, bioactivity, anti-inflammatory, antioxidant activity, and osteogenic activity. MBG/BSA bone grafts are proved to be biocompatible and can release bioactive ions including calcium and silicon in a sustained manner. Furthermore, MBG/BSA reprograms the macrophage phenotype toward anti-inflammation that is beneficial for bone regeneration. The antioxidative activity is also validated under inflammation and the mechanism may be via the interleukin-4 (IL-4)/Signal transducer and activator of transcription 6 (STAT6) pathway. The osteogenic differentiation and mineralization are also facilitated due to the improved immunoregulation of MBG/BSA. Overall, this work suggests that the MBG/BSA bone grafts with improved immunomodulatory properties are an ideal material for inflammatory bone regeneration application.

Crestal approach for maxillary sinus augmentation in individuals with limited alveolar bone height: An observational study

In cases where the bone presence is <4 mm, the lateral approach is typically the first approach considered. Nevertheless, for patients who prefer minimally invasive procedures or wish to reduce postoperative discomfort, the crestal approach is a viable option. The objective of this study was to investigate the potential of crestal sinus augmentation for achieving adequate bone in individuals with residual bone measuring <3 mm. The study comprised 11 participants (63.6 ± 10.9 years of age) who were treated at Seoul St. Mary's Hospital between 2021 and 2023 and received crestal approach sinus augmentation due to insufficient bone density of <3 mm using the crestal approach kit. Pre-augmentation and post-augmentation cone-beam computed tomographic images were analyzed using the imaging software to measure vertical bone height, bucco-palatal width, and mesio-distal width. Before the intervention, the height of the vertical bone was 2.1 ± 0.5 mm, while the width from buccal to palatal was 10.6 ± 2.9 mm, and the width from mesial to distal was 9.9 ± 1.2 mm. Following the intervention, these measurements increased to 8.8 ± 0.9 mm, 12.2 ± 2.2 mm, and 10.2 ± 1.2 mm, respectively. The change in height of the vertical bone was 6.7 ± 1.0 mm, in bucco-palatal width was 1.6 ± 1.4 mm, and in mesio-distal width was 0.3 ± 0.4 mm. The results revealed a significant rise in the height of the vertical bone and bucco-palatal width. Crestal sinus augmentation has been demonstrated to be a highly effective approach for achieving an adequate quantity of bone in patients with residual bone <3 mm. Nonetheless, further observation is required to evaluate the long-term prognosis of the procedures.

An Up-to-Date Review of Materials Science Advances in Bone Grafting for Oral and Maxillofacial Pathology

Bone grafting in oral and maxillofacial surgery has evolved significantly due to developments in materials science, offering innovative alternatives for the repair of bone defects. A few grafts are currently used in clinical settings, including autografts, xenografts, and allografts. However, despite their benefits, they have some challenges, such as limited availability, the possibility of disease transmission, and lack of personalization for the defect. Synthetic bone grafts have gained attention since they have the potential to overcome these limitations. Moreover, new technologies like nanotechnology, 3D printing, and 3D bioprinting have allowed the incorporation of molecules or substances within grafts to aid in bone repair. The addition of different moieties, such as growth factors, stem cells, and nanomaterials, has been reported to help mimic the natural bone healing process more closely, promoting faster and more complete regeneration. In this regard, this review explores the currently available bone grafts, the possibility of incorporating substances and molecules into their composition to accelerate and improve bone regeneration, and advanced graft manufacturing techniques. Furthermore, the presented current clinical applications and success stories for novel bone grafts emphasize the future potential of synthetic grafts and biomaterial innovations in improving patient outcomes in oral and maxillofacial surgery.

Hierarchical Biomaterial Scaffolds for Periodontal Tissue Engineering: Recent Progress and Current Challenges

The periodontium is a complex hierarchical structure composed of alveolar bone, periodontal ligament, cementum, and gingiva. Periodontitis is an inflammatory disease that damages and destroys the periodontal tissues supporting the tooth. Periodontal therapies aim to regenerate the lost tissues, yet current treatments lack the integration of multiple structural/biochemical instructive cues to induce a coordinated regeneration, which leads to limited clinical outcomes. Hierarchical biomaterial scaffolds offer the opportunity to recreate the organization and architecture of the periodontium with distinct compartments, providing structural biomimicry that facilitates periodontal regeneration. Various scaffolds have been fabricated and tested preclinically, showing positive regenerative results. This review provides an overview of the recent research on hierarchical scaffolds for periodontal tissue engineering (TE). First, the hierarchical structure of the periodontium is described, covering the limitations of the current treatments used for periodontal regeneration and presenting alternative therapeutic strategies, including scaffolds and biochemical factors. Recent research regarding hierarchical scaffolds is highlighted and discussed, in particular, the scaffold composition, fabrication methods, and results from in vitro/in vivo studies are summarized. Finally, current challenges associated with the application of hierarchical scaffolds for periodontal TE are debated and future research directions are proposed.

A parathyroid hormone related supramolecular peptide for multi-functionalized osteoregeneration

Supramolecular peptide nanofiber hydrogels are emerging biomaterials for tissue engineering, but it is difficult to fabricate multi-functional systems by simply mixing several short-motif-modified supramolecular peptides because relatively abundant motifs generally hinder nanofiber cross-linking or the formation of long nanofiber. Coupling bioactive factors to the assembling backbone is an ideal strategy to design multi-functional supramolecular peptides in spite of challenging synthesis and purification. Herein, a multi-functional supramolecular peptide, P1R16, is developed by coupling a bioactive factor, parathyroid hormone related peptide 1 (PTHrP-1), to the basic supramolecular peptide RADA16-Ⅰ via solid-phase synthesis. It is found that P1R16 self-assembles into long nanofibers and co-assembles with RADA16-Ⅰ to form nanofiber hydrogels, thus coupling PTHrP-1 to hydrogel matrix. P1R16 nanofiber retains osteoinductive activity in a dose-dependent manner, and P1R16/RADA16-Ⅰ nanofiber hydrogels promote osteogenesis, angiogenesis and osteoclastogenesis in vitro and induce multi-functionalized osteoregeneration by intramembranous ossification and bone remodeling in vivo when loaded to collagen (Col) scaffolds. Abundant red blood marrow formation, ideal osteointegration and adapted degradation are observed in the 50% P1R16/Col scaffold group. Therefore, this study provides a promising strategy to develop multi-functional supramolecular peptides and a new method to topically administrate parathyroid hormone or parathyroid hormone related peptides for non-healing bone defects.

Epithelial cyst following subepithelial connective tissue graft: A case report

BACKGROUND

Various surgical approaches have been employed to manage gingival recession, including subepithelial connective tissue grafting, which has yielded favorable outcomes.

METHODS AND RESULTS

We present the case of a 17-year-old patient who developed gingival recession on tooth #6 following an esthetic crown lengthening procedure. The recession was treated with a subepithelial connective tissue graft; however, this case details the occurrence of two epithelial cysts adjacent to the region subjected to the surgical procedure, 6 months after surgery. The treatment involved periodontal surgical intervention, during which the lesions were completely excised and the associated osseous defect was filled using an inorganic bovine bone matrix along with a collagen membrane. The healing progressed without any complications. Histopathological analysis revealed the presence of cystic lesions, which were characterized by a cystic cavity lined with stratified orthokeratinized epithelium with cuboidal cells in some areas surrounded by fibrous connective tissue. The patient's progress was monitored through tomography performed 6 months, 1 year, and 5 years post-procedure, all of which demonstrated the absence of any signs of lesion recurrence.

CONCLUSION

This case study emphasizes the effectiveness and predictability of subepithelial connective tissue grafting in the treatment of gingival recession. However, dental professionals should be cautious about the potential risk of gingival recession following esthetic crown lengthening procedures and recognize the potential complications associated with subepithelial connective tissue grafting, such as the observed development of epithelial cysts in this specific case.

KEY POINTS

Why is this case new information? We present a case of an epithelial cyst following a subepithelial connective tissue graft, which resulted in buccal cortical bone resorption. The treatment involved excisional biopsy and the use of an inorganic bovine bone matrix with a collagen membrane. What are the keys to the successful management of this case? Successful treatment included periodontal surgery, bone defect filling using an inorganic bovine bone matrix and a collagen membrane, and regular monitoring with CT scans at 6 months, 1 year, and 5 years post-surgery; all showed no recurrence. Success factors included careful surgery, appropriate biomaterial usage, and ongoing follow-up. What are the primary limitations to success in this case? The limitations involve potential complications from subepithelial connective tissue grafting such as cyst development. This report stresses the importance of meticulous patient selection and periodontal phenotype evaluation to minimize risks. Continuous follow-up is critical to detect recurrence and other issues.

Bone Allograft Acid Lysates Change the Genetic Signature of Gingival Fibroblasts

Bone allografts are widely used as osteoconductive support to guide bone regrowth. Bone allografts are more than a scaffold for the immigrating cells as they maintain some bioactivity of the original bone matrix. Yet, it remains unclear how immigrating cells respond to bone allografts. To this end, we have evaluated the response of mesenchymal cells exposed to acid lysates of bone allografts (ALBA). RNAseq revealed that ALBA has a strong impact on the genetic signature of gingival fibroblasts, indicated by the increased expression of IL11, AREG, C11orf96, STC1, and GK-as confirmed by RT-PCR, and for IL11 and STC1 by immunoassays. Considering that transforming growth factor-β (TGF-β) is stored in the bone matrix and may have caused the expression changes, we performed a proteomics analysis, TGF-β immunoassay, and smad2/3 nuclear translocation. ALBA neither showed detectable TGF-β nor was the lysate able to induce smad2/3 translocation. Nevertheless, the TGF-β receptor type I kinase inhibitor SB431542 significantly decreased the expression of IL11, AREG, and C11orf96, suggesting that other agonists than TGF-β are responsible for the robust cell response. The findings suggest that IL11, AREG, and C11orf96 expression in mesenchymal cells can serve as a bioassay reflecting the bioactivity of the bone allografts.