Comparison of different grafting materials for treatment of bone defect distal to the molar in canine

Alveolar ridge preservation of two-wall bone defects using mineralized dentin matrix: An experimental pre-clinical study

OBJECTIVES

To study bone healing of two-wall bone defects after alveolar ridge preservation using mineralized dentin matrix.

MATERIALS AND METHODS

After distal roots extraction of second and fourth premolars (P2, P4) on one lateral mandible in 12 beagles, two-wall bone defects (5 × 5 × 5 mm) were surgically created distally to the remaining mesial roots of P2 and P4. A total of 24 sites were randomly allocated to three groups (implant material- time of execution): mineralized dentin matrix (MDM)-3 m (MDM + collagen membrane; 3 months), MDM-6 m (MDM particles + collagen membrane; 6 months), and C-6 m (collagen membrane only; 6 months). Clinical, radiographic, digital, and histological examinations were performed 3 and 6 months after surgery.

RESULTS

The bone healing in MDM groups were better compared to Control group (volume of bone regenerated in total: 25.12 mm3 vs. 13.30 mm3, p = .046; trabecular volume/total volume: 58.84% vs. 39.18%, p = .001; new bone formation rate: 44.13% vs. 31.88%, p = .047). Vertically, the radiological bone level of bone defect in MDM-6 m group was higher than that in C-6 m group (vertical height of bone defect: 1.55 mm vs. 2.74 mm, p = .018). Horizontally, no significant differences in buccolingual bone width were found between MDM and C groups at any time or at any level below the alveolar ridge. The percentages of remaining MDM were <1% in both MDM-3 m and MDM-6 m groups.

CONCLUSIONS

MDM improved bone healing of two-wall bone defects and might be considered as a socket fill material used following tooth extraction.

Cross Talk Between Cells and the Current Bioceramics in Bone Regeneration: A Comprehensive Review

The conventional approach for addressing bone defects and stubborn non-unions typically involves the use of autogenous bone grafts. Nevertheless, obtaining these grafts can be challenging, and the procedure can lead to significant morbidity. Three primary treatment strategies for managing bone defects and non-unions prove resistant to conventional treatments: synthetic bone graft substitutes (BGS), a combination of BGS with bioactive molecules, and the use of BGS in conjunction with stem cells. In the realm of synthetic BGS, a multitude of biomaterials have emerged for creating scaffolds in bone tissue engineering (TE). These materials encompass biometals like titanium, iron, magnesium, and zinc, as well as bioceramics such as hydroxyapatite (HA) and tricalcium phosphate (TCP). Bone TE scaffolds serve as temporary implants, fostering tissue ingrowth and the regeneration of new bone. They are meticulously designed to enhance bone healing by optimizing geometric, mechanical, and biological properties. These scaffolds undergo continual remodeling facilitated by bone cells like osteoblasts and osteoclasts. Through various signaling pathways, stem cells and bone cells work together to regulate bone regeneration when a portion of bone is damaged or deformed. By targeting signaling pathways, bone TE can improve bone defects through effective therapies. This review provided insights into the interplay between cells and the current state of bioceramics in the context of bone regeneration.

Role of periosteum in alveolar bone regeneration comparing with collagen membrane in a buccal dehiscence model of dogs

To investigate the role of periosteum on the treatment of buccal dehiscence defects comparing with collagen membrane in canine model. Bilateral dehiscence-type defects at the buccal side on the distal root of the lower 3rd/4th premolars were created in six beagle dogs with a total of 24 defects and assigned into three groups: Group A: blood clot in an untreated defect; Group B: deproteinized bovine bone material (DBBM) covered with an absorbable membrane; Group C: DBBM covered with the periosteum. The structural parameters for trabecular architecture and vertical bone regeneration were evaluated. Histological and histomorphometric evaluation were carried out to observe new bone formation and mineralization in the graft site. Immunohistochemical analysis was performed to identify the expression of osteopontin (OPN) and osteocalcin (OCN) at postoperative 3 months. Group C achieved greater vertical alveolar bone gain than that of group A and group B. The periosteum-covered group showed significantly greater new bone formation and accelerated mineralization. The greater immunolabeling for OPN and OCN was observed in group C than in group A. Periosteal coverage has explicit advantages over collagen membranes for the quality and quantity of new bone regeneration in dehiscence defects repairing.

Applications of Biodegradable Magnesium-Based Materials in Reconstructive Oral and Maxillofacial Surgery: A Review

Reconstruction of defects in the maxillofacial region following traumatic injuries, craniofacial deformities, defects from tumor removal, or infections in the maxillofacial area represents a major challenge for surgeons. Various materials have been studied for the reconstruction of defects in the maxillofacial area. Biodegradable metals have been widely researched due to their excellent biological properties. Magnesium (Mg) and Mg-based materials have been extensively studied for tissue regeneration procedures due to biodegradability, mechanical characteristics, osteogenic capacity, biocompatibility, and antibacterial properties. The aim of this review was to analyze and discuss the applications of Mg and Mg-based materials in reconstructive oral and maxillofacial surgery in the fields of guided bone regeneration, dental implantology, fixation of facial bone fractures and soft tissue regeneration.

Feasibility and Efficacy of a Degradable Magnesium-Alloy GBR Membrane for Bone Augmentation in a Distal Bone-Defect Model in Beagle Dogs

We explored the feasibility and efficacy of a degradable magnesium (Mg) alloy guided bone regeneration (GBR) in the treatment of bone defects after tooth extraction. A GBR membrane (MAR-Gide (MG)) was used to treat a mandibular second molar (M2M)-distal bone defect (DBD). In eight beagle dogs, bilateral mandibular second and fourth premolars were hemi-sected. The distal roots were removed to create a two-wall bony defect of dimension 5 mm × 5 mm × 5 mm to simulate M2M-DBD. Thirty-two bone defects were assigned randomly into four groups according to GBR membranes (MG and Bio-Gide (BG)) applied and the time of killing (3 months and 6 months after surgery). The osteogenesis of bone defects and MG degradation were analyzed using micro-CT, histology (staining, tartrate-resistant acid phosphatase), and inductively coupled plasma mass spectrometry. MG did not increase the prevalence of infection, wound dehiscence, or subcutaneous emphysema compared with those using BG. Trabecular volume/total volume at 3 months (63.71 ± 10.4% vs. 59.97 ± 8.94%) was significantly higher in the group MG than that in the group BG. Implanted MG was degraded completely within 3 months, and "island-shaped" new bone was found near MG degradation products. A significant difference was not found in vertical bone height or percent of new bone formation (45.44 ± 12.28% vs. 43.49 ± 7.12%) between the groups. The concentration of rare-earth elements in mandibular lymph nodes of the group MG was significantly higher than that of the group BG (P ≤ 0.017) but did not lead to histopathological changes. In summary, MG exhibited good biocompatibility and clinical applicability compared with BG in vivo. The osteogenic effect of MG could be enhanced by regulating the degradation rate of Mg-alloy.

Application of deproteinized bovine bone mineral as proangiogenic scaffold for alveolar bone formation in beagle dogs

Alveolar bone repair after tooth extraction is essential after oral surgeries. Various grafting materials are used to promote the regeneration of lost alveolar bone. This study analysed the morphological features of the tissue regeneration process using deproteinized bovine bone mineral (DBBM). DBBM was used to densely fill the extraction sockets in beagle dogs. Following resin casting of the vasculature, stereomicroscopy and scanning electron microscopy were used to observe blood vessels and hard tissues in haematoxylin and eosin-stained sections on postoperative days 14, 30 and 90 in conjunction with vascular endothelial growth factor (VEGF) immunostaining to evaluate alveolar bone vascularization. On day 14 post-operation, the DBBM granules tightly filled the extraction sockets, maintained alveolar margin height and formed a scaffold for aiding angiogenesis and new bone formation. On day 30, new bone formation was observed around the DBBM granules. By day 90, bone tissue regeneration progressed in both groups but was more pronounced in the DBBM group. Alveolar margin height was maintained in the DBBM group throughout the study. Furthermore, VEGF expression in the DBBM group was detected around newly formed bone. We conclude that DBBM acts as a suitable scaffold for new bone generation, as well as angiogenesis around healing alveolar bone, and that it has the potential to play a key role in vascularization and bone formation.

A Review of the Functions of Matrix Vesicles in Periodontal Tissues

Periodontal tissues consist of cementum, periodontal ligaments, and alveolar bone, which provide indispensable support for physiological activities involving mastication, swallowing, and pronunciation. The formation of periodontal tissues requires a complex process, during which a close relationship with biomineralization is noticeable. Alveolar bone and cementum are physically hard, both of which are generated from biomineralization and possess the exact mechanical properties resembling other hard tissues. However, when periodontitis, congenital abnormalities, periapical diseases, and other pathological conditions affect the organism, the most common symptom, alveolar bone defect, is always unavoidable, which results in difficulties for current clinical treatment. Thus, exploring effective therapies to improve the prognosis is important. Matrix vesicles (MVs), a special subtype of extracellular vesicles related to histogenesis, are widely produced by the stem cells of developing hard tissues. With the assistance of the enzymes and transporters contained within them, MVs can construct the extracellular matrix and an adequate microenvironment, thus promoting biomineralization and periodontal development. Presently, MVs can be effectively extracted and delivered by scaffolds and generate hard tissues in vitro and in vivo, which are expected to be translated into therapies for alveolar bone defects. In this review, we generalize recent research progress on MV morphology, molecular composition, biological mechanism, and, in particular, the biological functions in periodontal development. In addition to the above unique roles of MVs, we further describe the available MV-related biotechnologies and achievements that make them promising for coping with existing problems and improving the treatment of alveolar bone defects.

Analysis of conference abstracts of prosthodontic randomised-controlled trials presented at IADR general sessions (2002-2015): a cross-sectional study of the relationship between demographic characteristics, reporting quality and final publication

OBJECTIVES

To analyse the relationship between demographic characteristics, reporting quality and final publication rate of conference abstracts of prosthodontic randomised-controlled trials (RCTs) presented at International Association for Dental Research (IADR) general sessions (2002-2015).

DESIGN

A cross-sectional study on conference abstracts.

METHODS

Conference abstracts of prosthodontic RCTs presented at IADR general sessions (2002-2015) were obtained. Literature search was performed in multiple databases to confirm the final publication status of conference abstracts. Two investigators independently extracted the data including conference date, origin, presentation type, exact p value, number of centres, institution type, overall conclusion, subspecialty, publication time and journal. The reporting quality of abstracts was assessed by two investigators according to the Consolidated Standards of Reporting Trials statement. The relationship between demographic characteristics, reporting quality and final publication was analysed by χ² test.

SETTING, PARTICIPANTS AND INTERVENTIONS

Not applicable.

PRIMARY AND SECONDARY OUTCOME MEASURES

Final publication rate, demographic characteristics and reporting quality of conference abstracts of prosthodontic RCTs presented at IADR general sessions (2002-2015).

RESULTS

Of the 340 prosthodontic RCT abstracts, 43.24% were published. The mean time to final publication was 22.86 months. Europe contributed the most number of abstracts but Asia and Australia had the highest publication rate. Oral presentation, multicentre trial and complete denture and overdenture subspecialty were associated with a higher publication rate. Reporting quality of eligibility criteria of participants, random assignment and primary outcome results for each group correlated with a higher final publication rate.

CONCLUSIONS

Over half of conference abstracts of prosthodontic RCTs presented at IADR general sessions (2002-2015) were unpublished. Oral presentation and multiple centres were associated with higher publication rates. Abstracts' reporting quality addressing participant recruitment, assignment and primary results correlated with trials' validity and applicability. Conference attendees may refer to this research to identify valid and applicable prosthodontic trials but should treat and apply results cautiously.

Effect of advanced platelet-rich fibrin on accelerating alveolar bone formation in dogs: a histological and immunofluorescence evaluation

Several methods have been developed to regenerate lost alveolar bone. Platelet-rich fibrin (PRF) is a useful adjunct for new bone formation in dentistry. To elucidate the effect of advanced PRF (A-PRF) on bone formation, we inserted A-PRF clots in sockets after tooth extraction. Premolars were extracted from beagle dogs, and A-PRF was applied to the socket. New bone formation was assessed using histological and immunofluorescence examinations, and the bone formation ratio was evaluated 14 and 30 days postoperatively. Histological examination revealed newly formed bone filling the sockets up to the center in the A-PRF group at 14 days postoperatively, while thick and regular bone trabeculae were arranged in porous bone after 30 days. Higher expressions of osteocalcin and osteopontin were observed in newly formed bone in the A-PRF group, compared to the control group. The bone formation ratio was also higher in the A-PRF group than in the control group. Thus, A-PRF application may result in enhanced new bone formation and may aid in accelerating bone formation. A-PRF was more rapid than a self-limiting process during induction of bone formation by enhancing osteoblast activity and may be useful for bone formation in clinical medicine.