Particulate Bone Research Articles

Computer-assisted contouring combined with bone ostectomy for dental implant placement of craniofacial fibrous dysplasia involving the right maxilla.

Craniofacial fibrous dysplasia (CFD) affecting the jaws can result in facial asymmetry, posing a unique challenge for dental implant placement in edentulous areas. This case report introduces an innovative approach for rehabilitating the posterior maxilla affected by CFD using a computer-guided technique for maxillary recontouring and substitution bone grafting at implant sites. A 58-year-old edentulous female with a craniofacial fibrous dysplasia bone lesion affecting the right maxilla was referred for correction of asymmetry and dental implant placement. A computer guide was devised for shaving and contouring the right maxilla. Following virtual maxillary reduction, a second guide was created over the osteomized 3D model to plan the location of future dental implants and guide bone ostectomies for allograft substitution. Particulate bone substitute was applied to ostectomy sites in the affected maxillary alveolar ridge. Four implants were placed successfully four months post-operation, with integration confirmed by clinical examination after one year of follow-up. This treatment approach emerges as a reliable and effective modality for simultaneous dental implant rehabilitation in edentulous alveolar bone and jaw contouring in CFD cases.

A Two-Stage Approach to Alveolar Clefts Repair with Combined Cortical and Cancellous Bone Grafting

Background: Achieving optimal efficacy in secondary alveolar bone grafting (SABG) poses a considerable challenge for patients with alveolar clefts post-canine eruption. This study introduces a novel technique called the "two-stage SABG" to improve the treatment outcomes for patients who have missed the optimal timing for bone grafting. Methods: Patients aged 12 and above, presenting with unilateral, complete alveolar clefts after canine eruption, were divided into two cohorts: conventional and two-stage groups. The two-stage group underwent oronasal fistula closure and mucoperiosteal sealing during the initial stage, followed by particulate cancellous bone marrow (PCBM) and mandibular cortical bone grafting in the second stage after a three-month interval. Six months after surgery, the SABG was evaluated quantitatively and qualitatively using computed tomography (CT). Results: A total of 81 patients (median age: 14 years; male/female: 49/32) were included in the conventional group, while the two-stage group consisted of 33 patients (19 years; 20/13). The two-stage group exhibited significantly superior outcomes (P < 0.01) in terms of radiographic healing rate (> 4 points) (96.97% vs. 55.56%), bone bridge height (12.17mm, IQRs=4.26mm), bone bridge width (9.09mm, IQRs=2.74mm), bone formation rate (69.73%, IQRs=22.73%), and bone resorption rate (48.85%, IQRs=22.57%). Additionally, the average three-dimensional deviations greater than 3.5mm at the affected piriform aperture margin. Conclusions: The novel two-stage SABG approach demonstrates significant benefits in the repair of alveolar clefts and pyriform foramen deformities through combined cortical and cancellous bone grafting.

Distribution of bone fragments in angled shots: an experimental study conducted on composite models containing artificial bone plates.

In conventional gunshot injuries to targets containing bone the resulting osseous fragments do not precede but follow the bullet on its further way through adjacent soft tissues. The term "secondary projectiles" for the particles does not appear to be appropriate since they are not believed to have enough energy necessary for creating their own wound channels away from the temporary cavity. Former studies have shown that in angled shots to glass panes the bulk of splinters does not follow the bullet's trajectory: The majority of the glass fragments, especially the larger ones, move at right angles to the pane shot through. The aim of the presented study was to examine whether osseous fragments behave like glass splinters in angled shots to flat synthetic bone. In this context, it should also be assessed, whether the bone fragments might act as secondary projectiles in rare cases. To answer these questions, test shots were fired to composite models consisting of flat synthetic bone and ballistic gelatin. Pistol cartridges 9mm Luger were used to fire the shots which were video-documented with a high-speed camera. Afterwards, the composite models underwent CT examination and macroscopic inspection. Video-documentation revealed that the larger bone particles from the perforation site move at a roughly right angle from the osseous sheet into the gelatin, causing an eccentric bulge of the temporary cavity. The smaller bone fragments were also lodged along the bullet's path, predominantly in the cracks radiating from the permanent wound channel.

Miliary Osteoma Cutis, Report of A Case After Plant Injury

Osteoma cutis (OC) is a rare condition characterized by the presence of bone particles within the skin. One subtype of osteoma cutis is miliary osteoma cutis (MOC), which primarily affects middle-aged women and commonly occurs on the face. Clinical features of MOC include papules and skin-colored hard nodules, similar to milia. In this case, we present a 60-year-old woman with facial skin lesions resulting from a plant injury. The diagnosis was miliary osteoma cutis, and successful surgical treatment was performed

Does Injectable Platelet-Rich Fibrin Combined With Autogenous Demineralized Dentine Enhance Alveolar Ridge Preservation? A Randomized Controlled Trial.

The present trial evaluated the first-time application of autogenous demineralized dentin graft with injectable platelet-rich fibrin (ADDG + i-PRF) versus autogenous demineralized dentin graft (ADDG), in alveolar ridge preservation (ARP) in the maxillary aesthetic zone. Twenty-two maxillary (n = 22) non-molar teeth indicated for extraction were randomized into two groups (n = 11/group). Extracted teeth were prepared into ADDG, implanted into extraction sockets with or without i-PRF amalgamation and covered by collagen sponge. Cone-beam computed tomography scans at baseline and 6 months were compared to assess ridge-dimensional changes. Keratinized tissue width, patient satisfaction, pain score and chair time were recorded. In the course of dental implant placements at 6 months, bone core biopsies of engrafted sites were obtained and analysed histomorphometrically. Reduction in ridge width was 1.71 ± 1.08 and 1.8 ± 1.35 mm, while reduction in ridge height was 1.11 ± 0.76 and 1.8 ± 0.96 mm for ADDG + i-PRF and ADDG, respectively (p > 0.05). Significant differences in keratinized tissue width reduction were notable between ADDG + i-PRF and ADDG (0.12 ± 0.34 and 0.58 ± 0.34 mm respectively; p = 0.008). Postoperative pain scores were significantly lower in ADDG + i-PRF (p = 0.012). All patients in the two groups were satisfied with no differences in chair time (p > 0.05). No differences in total percentage area of newly formed bone, soft tissue or graft particles were observed between the groups (p > 0.05). ADDG alone or in combination with i-PRF yields similar results regarding ARP clinically, quality of the formed osseous tissues, as well as patients' satisfaction. Yet, the addition of i-PRF to ADDG tends to preserve the keratinized tissue and lessen postoperative pain.

A conservative treatment of an involved molar tooth associated with dentigerous cyst: a case report and literature review

BackgroundDentigerous cysts (DCs) are among the most frequently odontogenic cysts in young and middle-aged individuals. Marsupialization and enucleation are the main treatment options in clinical practice. However, there are few reports on preserving molars severely involved by the cyst.Case presentationA 35-year-old male patient with a large odontogenic cyst that was successfully treated using a multidisciplinary approach. The patient’s chief complaint was discomfort during mastication in the lower left molar region for a month. Clinical examination revealed that teeth 36 and 37 were intact without pain upon percussion, while tooth 38 was unerupted. The radiology examination illustrated a typical well-defined oval radiolucent lesion surrounding the crown of unerupted tooth 38, extending to the distal root of tooth 37. The treatment was divided into two parts: removal of the cyst and the impacted third molar, followed by filling with collagen bone particles; and preserving the tooth 37 via hemisection, root canal treatment and crown restoration. Pathological examination indicated a dentigerous cyst. After 18 months of treatment, the bone defect completely recovered and tooth 37 functioned well following the hemisection.ConclusionsHemisection effectively preserves the cyst-associated molars and maintains oral function. This article underscores the significance of collaboration among various departments in the treatment of odontogenic cysts, ultimately aiming to achieve minimally invasive and functional surgery.

Clinical outcomes of using operating microscope for alveolar ridge preservation: A randomized controlled trial.

The use of the operating microscope (OM) for extraction and alveolar ridge augmentation (ARP) is increasing due to enhanced magnification and illumination. The primary objective was to compare the wound healing and crestal bone quality after the use of OM and dental loupes (DL) for ARP. Forty non-molar teeth with periapical lesions in need of extraction and ARP from 33 patients were randomly assigned to 2 groups: DL (control) or OM (test). All procedures were performed by 1 surgeon and assessments done by masked examiners. ARP was performed with an allograft and a resorbable collagen membrane. The presence of granulomatous tissue remnants after debridement was recorded. Cone-beam computed tomography (CBCT) and ultrasound (US) scans were taken during the healing phase up to 16-week visits. Bone cores were retrieved from implant osteotomies for histologic analysis. Patient-reported outcome measurements (PROMs) were assessed. All patients completed all study visits except 1 who dropped out before the last visit. After socket debridement, the test group exhibited significantly fewer sites with tissue remnants (p=0.01) and a better healing score at 2-week (p=0.04) and 4-week (p=0.01) time points. There were no significant differences in 12-week crestal bone healing by histology (p=0.1), US (p=0.85), and CBCT healing (p=0.64) at 12weeks, as well as PROMs (p>0.1). Within the limitation of the study, the use of OM for ARP resulted in significantly fewer tissue remnants and favorable early visual wound healing. CBCT and US-derived-crestal bone quality did not show a difference between the 2 groups. Alveolar ridge preservation (ARP) by placing bone particulates in the extraction socket, covered by a wound dressing material, is commonly applied immediately after tooth extraction to reduce jawbone shrinkage in preparation for implant placement later. The jawbone healing varies, depending largely on the ability to remove the etiology, socket features, extent of surgical trauma, and wound stability. Healed jawbone with good quality is favorable for easiness of implant placement and could be related to maintenance of long-term implant health. The surgical microscope with high magnification (up to ∼25×) and co-axial illumination is ideal for assistance in the removal of granulomatous tissue that is believed to interfere with healing, performance of minimally invasive extraction, and stabilization of the wound with meticulous tissue management and fine sutures. This study compared the use of the surgical microscope to dental loupes for ARP in a randomized controlled design. The microscope-assisted ARP is associated with a significantly higher chance of removing granulomatous tissue, favorable early healing, and similar crestal bone quality. Removal of granulomatous tissue is significant for immediate implant placement. This study serves as a model for testing the benefits of the surgical microscope for encouraging early healing in more challenging intraoral surgical procedures.

Enhanced alveolar ridge preservation with hyaluronic acid-enriched allografts: a comparative study of granular allografts with and without hyaluronic acid addition

PurposeRidge preservation is essential to restore alveolar ridge volume and to enhance esthetic and functional outcomes for dental implants. The addition of hyaluronic acid to allogeneic bone substitute materials might enhance these outcomes. This clinical study evaluated the efficacy of ridge preservation after tooth extraction using granular allografts with and without hyaluronic acid addition.MethodsIn this retrospective study, 40 patients with compromised extraction sockets were enrolled. Among them, 19 received particulate allogeneic bone substitutes (Allo), 21 received allogeneic bone substitutes with hyaluronic acid (AlloHya). Vertical and horizontal graft stability, graft shrinkage rate, and bone mineral density were assessed using radiographic measurements on CBCT scans conducted before tooth extraction, directly after ridge preservation and after four months. Patients were followed up 12 months post-implantation.ResultsVertical height loss after 4 months was significantly greater in the Allo group (-0.82 ± 0.95 mm) compared to the AlloHya group (-0.19 ± 0.51 mm; p = 0.011). Graft shrinkage rate was 16.9 ± 11.5% (Allo) and 10.3 ± 7.7% (AlloHya) (p = 0.038). After four months, average bone density was significantly higher in the AlloHya compared to the Allo group (p = 0.004). Nearly all implants (39 out of 40) were classified as “Success” according to the ICOI scheme, with no differences in implant quality between the two study groups.ConclusionsImproved graft stability, reduced resorption, and increased bone density were observed in hyaluronic acid-enriched allografts compared to pure allografts. Adding hyaluronic acid to allogeneic bone grafts significantly enhanced outcomes in ridge preservation.

Arthroscopic removal of the fragmented medial coronoid process in dogs - Evaluation of treatment results with special reference to postoperative computed tomography and residual particles

The aim of this study was to assess the treatment success of dogs with medial coronoid disease (here: Fragmented Coronoid Process [FCP]) following arthroscopically performed subtotal coronoidectomy by the use of subjective and objective gait analysis and the evaluation of osteoarthritis progression in addition to their correlation with the findings from postoperative computed tomography. In particular, the clinical relevance of residual particles remaining postoperatively was to be evaluated. Thirty elbows from 24 dogs of different breeds were examined clinically, orthopedically, using gait analysis as well as radiographically at least 6 months after unilateral or bilateral subtotal coronoidectomy. The results were compared with the preoperative findings of the corresponding examinations and postoperative computed tomography. 79.2% (19/24) of the patients improved by at least one degree of lameness in the orthopedic examination, 66.7% (16/24) were free of lameness. 60% (18/30 joints) showed an increase in the degree of arthrosis. Postoperative computed tomography revealed small residual bone particles (<1 mm) in the joint space or soft tissue in 56.7% (17/30) of the joints. No significant association was evident between residual lameness and residual particles remaining within the joint postoperatively. An association between persistent lameness and progression of arthrosis was also not be demonstrable. No evidence was apparent supporting a link between residues of small bone particles after arthroscopic subtotal coronoidectomy and postoperative lameness. The progression of osteoarthritis could not be interrupted despite the surgical intervention. When small residual particles (<1 mm) remain after subtotal coronoidectomy, these do not appear to have any influence on the clinical outcome.

Suppression of aerosol dispersion by highly viscoelastic poly(acrylic acid)- and poly(ethylene oxide)-based coolants during bone drilling

Bone drilling in neurosurgical, dental, and orthopedic procedures, combined with the use of coolants, generates a dispersion of bone particles, coolants, and blood aerosols in the air. This poses the threat of airborne transmission of infectious diseases between patients and medical practitioners. Highly viscoelastic polymeric poly(acrylic acid) (PAA) and poly(ethylene oxide) (PEO) solutions of various concentrations were used as coolants during bone drilling at different mass flow rates to suppress aerosol generation, thereby mitigating the threat of cross-infection. The results revealed that the PAA and PEO solutions provide less advection than water and a comparable cooling performance. However, excessive viscoelasticity of PEO causes the fluid to rise along the cutting burr (the Weissenberg effect), thereby reducing the cooling coverage area. In contrast, slightly lower viscoelasticity of PEO results in a high cooling coverage area. The cooling coverage area is smaller for the PAA at 20 ml/min because the corresponding PAA solution easily swirls or splashes away from the drilling location. However, at 80 ml/min, the supplied PAA solution sufficiently cools the drilling area, despite the loss through splashing. The numbers of atomized droplets of water and the PAA and PEO solutions were quantified and compared to investigate the degree of aerosol formation and dispersion. The solution with the strongest viscoelasticity most significantly suppressed aerosolization and produced the fewest dispersed aerosol droplets during bone drilling.

Application of decalcified bone matrix in Salmon bone for tibial defect repair in rat model.

The optimal preparation conditions of Salmon decalcified bone matrix (S-DBM) were explored, and the properties of S-DBM bone particles and bone powder were studied respectively. The therapeutic effect of S-DBM on tibial defect in female Sprague Dawley (SD) rats was preliminarily verified. This study assessed the structural and functional similarities of Salmon bone DBM (S-DBM). The biocompatibility assessment was conducted using both in vivo and in vitro experiments, establishing an animal model featuring tibial defects in rats and on the L929 cell line, respectively. The control group, bovine DBM (bDBM), was compared to the S-DBM-treated tibial defect rats. Imaging and histology were used to study implant material changes, defect healing, osteoinductive repair, and degradation. The findings of our study indicate that S-DBM exhibits favorable repairing effects on bone defects, along with desirable physicochemical characteristics, safety, and osteogenic activity. The S-DBM holds significant potential as a medical biomaterial for treating bone defects, effectively fulfilling the clinical demands for materials used in bone tissue repair engineering.

Healing patterns of alveolar bone following ridge preservation procedures.

Examine the histomorphometric bone composition, following alveolar ridge preservation techniques and unassisted socket healing. Forty-two patients (42) requiring a single rooted tooth extraction were randomly allocated into three groups (n = 14 per group): Group 1: Guided Bone Regeneration (GBR) using deproteinised bovine bone mineral (DBBM) and a porcine collagen membrane; Group 2: Socket Seal (SS) technique using DBBM and a porcine collagen matrix; Group 3: Unassisted socket healing (Control). Trephined bone biopsies were harvested following a 4-month healing period. Forty-two samples underwent Back-Scattered Electrons -Scanning Electron Microscopy (BSE-SEM) imaging, with 15 samples examined using Xray Micro-Tomography (XMT) (n = 6 for each GBR/SS and n = 3 Control). Images were analysed to determine the percentage (%) of connective tissue, new bone formation, residual DBBM particles and direct bone to DBBM particle contact (osseointegration). BSE-SEM analysis demonstrated that new bone formation was higher in the Control (45.89% ± 11.48) compared to both GBR (22.12% ± 12.7/p < .004) and SS (27.62% ± 17.76/p < .005) groups. The connective tissue percentage in GBR (49.72% ± 9), SS (47.81% ± 12.57) and Control (47.81% ± 12.57) groups was similar. GBR (28.17% ± 16.64) and SS (24.37% ± 18.61) groups had similar levels of residual DBBM particles. XMT volumetric analysis indicated a lower level of bone and DBBM particles in all test groups, when matched to the BSE-SEM area measurements. Osseointegration levels (DBBM graft and bone) were recorded at 35.66% (± 9.8) for GBR and 31.18% (± 19.38) for SS. GBR and SS ARP techniques presented with less bone formation when compared to unassisted healing. GBR had more direct contact/osseointegration between the DBBM particles and newly formed bone.

Ambient PM2.5 components might exacerbate bone loss among middle-aged and elderly women: evidence from a population-based cross-sectional study.

Previous studies have primarily focused on the links between fine particulate matter (PM2.5) and bone health among the general population instead of PM2.5 components and the specific population. We aimed to investigate the associations between PM2.5 components and bone health among middle-aged and elderly women. A total of 748 middle-aged and elderly women were randomly sampled from 32 streets/villages in Hubei Province. The concentrations of ambient PM2.5 and its components were extracted across various residential areas from the Tracking Air Pollution in China (TAP) dataset. Bone mineral density measurements were obtained from dual-energy X-ray absorptiometry scans of study participants. Multivariable logistic and linear models were employed to assess the relationship between PM2.5 and its components and bone loss. Per interquartile range (IQR) increase in nitrate (NO3-) and ammonium (NH4+) concentrations were associated with 1.65 [95% confidence intervals (CI): 1.13, 2.30] and 1.77 (95% CI: 1.26, 2.49) times higher odds of osteoporosis, respectively. Long-term exposure to sulfate (SO42-), NO3-, and NH4+ was negatively associated with T-scores and bone mineral density in L1-L4 lumbar vertebrae. In addition, the elderly, women who have experienced menarche after the age of 14, and postmenopausal women were more susceptible to the water-soluble inorganic salts of PM2.5. The study emphasizes the need for comprehensive policies addressing air quality, with a specific focus on vulnerable populations such as middle-aged and elderly women. Public health interventions aimed at reducing ambient PM2.5 concentrations and minimizing exposure to its harmful components are crucial in mitigating the adverse impact on skeletal health and improving the overall well-being of communities.

Sinus Floor Augmentation with Synthetic Hydroxyapatite (NanoBone®) in Combination with Platelet-Rich Fibrin: A Case Series.

Several techniques have been described for maxillary sinus graft augmentation, including the lateral window technique and crestal approach with osteotomes or osseodensification. Platelet-rich fibrin has been used in maxillary sinus lift procedures due to its ability to accelerate soft and hard tissue healing. The aim of this study was to evaluate the potential of PRF in combination with the synthetic hydroxyapatite NanoBone® to enhance bone regeneration in sinus floor elevation with the lateral window technique. Out of the 50 individuals screened in a preoperative assessment visit from the CESPU-Famalicão clinical unit and intervened upon between January 2023 and December 2023, only 6 patients who met the study's inclusion criteria consented to participate. In a split-mouth study, twelve sinus graft surgeries were carried out. Our observations reveal that for the test group (NanoBone®/PRF), there is a 27.5 ± 4.9% increase new vital bone, 23.0 ± 3.7% increase in inert bone particles, and 49.4 ± 2.8% increase in connective tissue. Meanwhile, for the control group (NanoBone®), there is a 19.5 ± 3.0% increase in new vital bone, 23.4 ± 5.7% increase in inert bone particles, and 57.0 ± 3.5% increase in connective tissue. The results strongly indicate that mixing liquid PRF with NanoBone® does not have a negative influence on the amount of viable bone formation, and it seems to slightly increase the amount of new bone formation and revascularization in sinus bone graft procedures with the lateral window technique compared to the single use of NanoBone®.

Photo-crosslinkable hydrogel incorporated with bone matrix particles for advancements in dentin tissue engineering.

The objective of this study was to create injectable photo-crosslinkable biomaterials, using gelatin methacryloyl (GelMA) hydrogel, combined with a decellularized bone matrix (BMdc) and a deproteinized (BMdp) bovine bone matrix. These were intended to serve as bioactive scaffolds for dentin regeneration. The parameters for GelMA hydrogel fabrication were initially selected, followed by the incorporation of BMdc and BMdp at a 1% (w/v) ratio. Nano-hydroxyapatite (nHA) was also included as a control. A physicochemical characterization was conducted, with FTIR analysis indicating that the mineral phase was complexed with GelMA, and BMdc was chemically bonded to the amide groups of gelatin. The porous structure was preserved post-BMdc incorporation, with bone particles incorporated alongside the pores. Conversely, the mineral phase was situated inside the pore opening, affecting the degree of porosity. The mineral phase did not modify the degradability of GelMA, even under conditions of type I collagenase-mediated enzymatic challenge, allowing hydrogel injection and increased mechanical strength. Subsequently, human dental pulp cells (HDPCs) were seeded onto the hydrogels. The cells remained viable and proliferative, irrespective of the GelMA composition. All mineral phases resulted in a significant increase in alkaline phosphatase activity and mineralized matrix deposition. However, GelMA-BMdc exhibited higher cell expression values, significantly surpassing those of all other formulations. In conclusion, our results showed that GelMA-BMdc produced a porous and stable hydrogel, capable of enhancing odontoblastic differentiation and mineral deposition when in contact with HDPCs, thereby showing potential for dentin regeneration.

A rhinopithecus swarm optimization algorithm for complex optimization problem

This paper introduces a novel meta-heuristic algorithm named Rhinopithecus Swarm Optimization (RSO) to address optimization problems, particularly those involving high dimensions. The proposed algorithm is inspired by the social behaviors of different groups within the rhinopithecus swarm. RSO categorizes the swarm into mature, adolescent, and infancy individuals. Due to this division of labor, each category of individuals employs unique search methods, including vertical migration, concerted search, and mimicry. To evaluate the effectiveness of RSO, we conducted experiments using the CEC2017 test set and three constrained engineering problems. Each function in the test set was independently executed 36 times. Additionally, we used the Wilcoxon signed-rank test and the Friedman test to analyze the performance of RSO compared to eight well-known optimization algorithms: Dung Beetle Optimizer (DBO), Beluga Whale Optimization (BWO), Salp Swarm Algorithm (SSA), African Vultures Optimization Algorithm (AVOA), Whale Optimization Algorithm (WOA), Atomic Retrospective Learning Bare Bone Particle Swarm Optimization (ARBBPSO), Artificial Gorilla Troops Optimizer (GTO), and Harris Hawks Optimization (HHO). The results indicate that RSO exhibited outstanding performance on the CEC2017 test set for both 30 and 100 dimension. Moreover, RSO ranked first in both dimensions, surpassing the mean rank of the second-ranked algorithms by 7.69% and 42.85%, respectively. Across the three classical engineering design problems, RSO consistently achieves the best results. Overall, it can be concluded that RSO is particularly effective for solving high-dimensional optimization problems.

Mechanical and in vitro study of 3D printed silk fibroin and bone-based composites biomaterials for bone implant application.

When treating orthopaedic damage or illness and accidental fracture, bone grafting remains the gold standard of treatment. In cases where this approach does not seem achievable, bone tissue engineering can offer scaffolding as a substitute. Defective and fractured bone tissue is extracted and substituted with porous scaffold structures to aid in the process of tissue regeneration. 3D bioprinting has demonstrated enormous promise in recent years for producing scaffold structures with the necessary capabilities. In order to create composite biomaterial inks for 3D bioprinting, three different materials were combined such as silk fibroin, bone particles, and synthetic biopolymer poly (ε-caprolactone) (PCL). These biomaterials were used to fabricate the two composites scaffolds such as: silk fibroin + bovine bone (SFB) and silk fibroin + bovine bone + Polycaprolactone (SFBP). The biomechanical, structural, and biological elements of the manufactured composite scaffolds were characterized in order to determine their suitability as a possible biomaterial for the production of bone tissue. The in vitro bioactivity of the two composite scaffolds was assessed in the simulated body fluids, and the swelling and degradation characteristics of the two developed scaffolds were analyzed separately over time. The results showed that the mechanical durability of the composite scaffolds was enhanced by the bovine bone particles, up to a specific concentration in the silk fibroin matrix. Furthermore, the incorporation of bone particles improved the bioactive composite scaffolds' capacity to generate hydroxyapatite in vitro. The combined findings show that the two 3D printed bio-composites scaffolds have the required mechanical strength and may be applied to regeneration of bone tissue and restoration, since they resemble the characteristics of native bone.

In vitro and in vivo investigation of antibacterial silver nanoparticles functionalized bone grafting substitutes.

Infection is a major concern in surgery involving grafting and should be considered thoroughly when designing biomaterials. There is considerable renewed interest in silver nanoparticles (AgNPs) owing to their ability to potentiate antibacterial properties against multiple bacterial strains. This study aimed to develop two antibacterial bone regenerative scaffolds by integrating AgNPs in bovine bone particles (BBX) (Product 1), and a light cross-linked hydrogel GelMA (Product 2). The constructs were characterized using scanning electron microscopy. Metabolic activity of osteoblasts and osteoclasts on the constructs was investigated using PrestoBlue™. Disk diffusion assay was conducted to test the antibacterial properties. The regenerative capacity of the optimized AgNP functionalized BBX and GelMA were tested in a rabbit cranial 6 mm defect model. The presence of AgNPs appears to enhance proliferation of osteoblasts compared to AgNP free controls in vitro. We established that AgNPs can be used at a 100 μg dose that inhibits bacteria, with minimal adverse effects on the bone cells. Our rabbit model revealed that both the BBX and GelMA hydrogels loaded AgNPs were biocompatible with no signs of necrosis or inflammatory response. Grafts functionalized with AgNPs can provide antibacterial protection and simultaneously act as a scaffold for attachment of bone cells.

Fish Bones as Calcium Source: Bioavailability of Micro and Nano Particles.

The amount of by-products/waste in the fish industry is roughly 50%. Fish bones could be used to produce nanoparticles, which may have potential use in the food industry as a novel calcium source and at the same time, contribute to reduce waste production. The objective of this study was to evaluate the bioavailability of nano-size salmon fish bone particles compared to micro-size salmon fish bone particles, and calcium carbonate. The study was carried out in 21-28-day-old C57BL/6 male mice fed for 21 days with the experimental diets. The groups were as follows: CaCO3 0.5% Ca (CN 0.5); CaCO3 1.0% Ca (CN 1.0); salmon fish bone (SFB) microparticles 0.5% Ca (MP 0.5); SFB microparticles 1.0% Ca (MP 1.0); SFB nanoparticles 0.5% Ca (NP 0.5); and SFB nanoparticles 1.0% Ca (NP 1.0). Calcium bioavailability, defined as the percent calcium in femur showed an increasing trend from CN 0.5 to NP 1.0 group. According to ANCOVA, the greatest Ca content was observed in the NP 1.0 group compared with all groups but NP 0.5. In conclusion, in a murine model, salmon fish bone nanoparticles present higher calcium bioavailability than salmon fish bone microparticles, and both, in turn, have better bioavailability than calcium carbonate.

Effects of intentional early dense‐polytetrafluoroethylene membrane removal on vertical ridge augmentation

AbstractBackgroundVertical ridge augmentation (VRA) requires long healing times for bone maturation. This case study deals with the intentional early removal of a titanium‐reinforced dense polytetrafluoroethylene (TR‐dPTFE) membrane that allowed for treatment times reduction and improvement of bone quality.MethodsA TR‐dPTFE membrane was used for VRA in the premolar region of the upper right maxilla. The defect was filled with a mix of particulate autogenous bone and porcine xenograft in a 1:1 ratio. After a 4‐month uneventful healing period, the membrane was removed, and the thick keratinized palatal tissue was moved toward the buccal side via a pedicle flap. Implants insertion and healing abutments application were carried out 3 months later, when bone graft could have been revascularized and nourished by the periosteum.ResultsThe histologic evaluation of a bone sample harvested during implant bed preparation revealed a huge amount of mature newly formed bone even in the most coronal part. Two screw‐retained crowns were delivered 2 months after implant insertion and the 3.5‐year follow‐up showed perfectly maintained hard and soft tissues.ConclusionsIntentional early removal of TR‐dPTFE membrane after a 4‐month healing time, with simultaneous soft tissue augmentation via a buccally reposioned pedicle flap, allowed graft revascularization from the periosteum, and resulted in optimal quantity and quality of the regenerated bone. This process shortened the overall treatment times, taking only 9 months from VRA to prosthetic loading. Both augmented hard and soft tissues allowed for crestal bone maintenance around implants.Key points Titanium‐reinforced dense polytetrafluoroethylene (TR‐dPTFE) membranes, due to their closed structure, do not allow the passage of cells and vessels from the periosteum, and revascularization from the residual bone alone is not enough for proper graft maturation and long‐term crestal bone maintenance. Early removal of TR‐dPTFE membrane allows graft revascularization from the periosteum, and results in optimal quantity and quality of the regenerated bone. Increasing the thickness of the soft tissues, increasing the width of the keratinized mucosa, and repositioning the mucogingival line, via a free gingival graft or a pedicle flap, should be performed simultaneously in the membrane removal phase to reduce the number of surgical interventions, decrease patient morbidity, and shorten the total treatment time.