Considering the important factor of bioactive nanohydoxyapatite (nHA) to enhance osteoconductivity or bone-bonding capacity, nHA was incorporated into an electrospun polycaprolactone (PCL) membrane using electrospinning techniques. The viscosity of the PCL and nHA/PCL with different concentrations of nHA was measured and the morphology of the electrospun membranes was compared using a field emission scanning electron microscopy. The water contact angle of the nanofiber determined the wettability of the membranes of different concentrations. The surface roughness of the electrospun nanofibers fabricated from pure PCL and nHA/PCL was determined and compared using atomic force microscopy. Attenuated total reflectance Fourier transform infrared spectroscopy was used to study the chemical bonding of the composite electrospun nanofibers. Beadless nanofibers were achieved after the incorporation of nHA with a diameter of 200-700 nm. Results showed that the fiber diameter and the surface roughness of electrospun nanofibers were significantly increased after the incorporation of nHA. In contrast, the water contact angle (132° ± 3.5°) was reduced for PCL membrane after addition of 10% (w/w) nHA (112° ± 3.0°). Ultimate tensile strengths of PCL membrane and 10% (w/w) nHA/PCL membrane were 25.02 ± 2.3 and 18.5 ± 4.4 MPa. A model drug tetracycline hydrochloride was successfully loaded in the membrane and the membrane demonstrated good antibacterial effects against the growth of bacteria by showing inhibition zone for E. coli (2.53 ± 0.06 cm) and B. cereus (2.87 ± 0.06 cm).
Morphological surface modifications have been reported to enhance the performance of biomedical implants. However, current methods of introducing graded porosity involves postprocessing techniques that lead to formation of microcracks, delamination, loss of fatigue strength, and, overall, poor mechanical properties. To address these issues, we developed a microwave sintering procedure whereby pure titanium powder can be readily densified into implants with graded porosity in a single step. Using this approach, surface topography of implants can be closely controlled to have a distinctive combination of surface area, pore size, and surface roughness. In this study, the effect of various surface topographies on in vitro response of neonatal rat calvarial osteoblast in terms of attachment and proliferation is studied. Certain graded surfaces nearly double the chance of cell viability in early stages (∼one month) and are therefore expected to improve the rate of healing. On the other hand, while the osteoblast morphology significantly differs in each sample at different periods, there is no straightforward correlation between early proliferation and quantitative surface parameters such as average roughness or surface area. This indicates that the nature of cell-surface interactions likely depends on other factors, including spatial parameters.
Matched MeSH terms: Bone and Bones/drug effects; Bone and Bones/pathology*
Hypoxia, the result of disrupted vasculature, can be categorized in the main limiting factors for fracture healing. A lack of oxygen can cause cell apoptosis, tissue necrosis, and late tissue healing. Remedying hypoxia by supplying additional oxygen will majorly accelerate bone healing. In this study, biphasic calcium phosphate (BCP) scaffolds were fabricated by robocasting, an additive manufacturing technique. Then, calcium peroxide (CPO) particles, as an oxygen-releasing agent, were coated on the BCP scaffolds. Segmental radial defects with the size of 15 mm were created in rabbits. Uncoated and CPO-coated BCP scaffolds were implanted in the defects. The empty (control) group received no implantation. Repairing of the bone was investigated via X-ray, histological analysis, and biomechanical tests at 3 and 6 months postoperatively, with immunohistochemical examinations at 6 months after operation. According to the radiological observations, formation of new bone was augmented at the interface between the implant and host bone and internal pores of CPO-coated BCP scaffolds compared to uncoated scaffolds. Histomorphometry analysis represented that the amount of newly formed bone in the CPO-coated scaffold was nearly two times higher than the uncoated one. Immunofluorescence staining revealed that osteogenic markers, osteonectin and octeocalcin, were overexpressed in the defects treated with the coated scaffolds at 6 months of postsurgery, demonstrating higher osteogenic differentiation and bone mineralization compared to the uncoated scaffold group. Furthermore, the coated scaffolds had superior biomechanical properties as in the case of 3 months after surgery, the maximal flexural force of the coated scaffolds reached to 134 N, while it was 92 N for uncoated scaffolds. The results could assure a boosted ability of bone repair for CPO-coated BCP scaffolds implanted in the segmental defect of rabbit radius because of oxygen-releasing coating, and this system of oxygen-generating coating/scaffold might be a potential for accelerated repairing of bone defects.
Bone degeneration associated with various diseases is increasing due to rapid aging, sedentary lifestyles, and unhealthy diets. Living bone tissue has bioelectric properties critical to bone remodeling, and bone degeneration under various pathological conditions results in significant changes to these bioelectric properties. There is growing interest in utilizing biomimetic electroactive biomaterials that recapitulate the natural electrophysiological microenvironment of healthy bone tissue to promote bone repair. This review first summarizes the etiology of degenerative bone conditions associated with various diseases such as type II diabetes, osteoporosis, periodontitis, osteoarthritis, rheumatoid arthritis, osteomyelitis, and metastatic osteolysis. Next, the diverse array of natural and synthetic electroactive biomaterials with therapeutic potential are discussed. Putative mechanistic pathways by which electroactive biomaterials can mitigate bone degeneration are critically examined, including the enhancement of osteogenesis and angiogenesis, suppression of inflammation and osteoclastogenesis, as well as their anti-bacterial effects. Finally, the limited research on utilization of electroactive biomaterials in the treatment of bone degeneration associated with the aforementioned diseases are examined. Previous studies have mostly focused on using electroactive biomaterials to treat bone traumatic injuries. It is hoped that this review will encourage more research efforts on the use of electroactive biomaterials for treating degenerative bone conditions.
The use of bioceramics, especially the combination of hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP), as a three-dimensional scaffold in bone engineering is essential because together these elements constitute 60% of the bone content. Different ratios of HA and β-TCP were previously tested for their ability to produce suitable bioceramic scaffolds, which must be able to withstand high mechanical load. In this study, two ratios of HA/TCP (20:80 and 70:30) were used to create pellets, which then were evaluated in vitro to identify any adverse effects of using the material in bone grafting. Diametral tensile strength (DTS) and density testing was conducted to assess the mechanical strength and porosity of the pellets. The pellets then were tested for their toxicity to normal human fibroblast cells. In the toxicity assay, cells were incubated with the pellets for 3 days. At the end of the experiment, cell morphological changes were assessed, and the absorbance was read using PrestoBlue Cell Viability Reagent™. An inversely proportional relationship between DTS and porosity percentage was detected. Fibroblasts showed normal cell morphology in both treatments, which suggests that the HA/TCP pellets were not toxic. In the osteoblast cell attachment assay, cells were able to attach to the surface of both ratios, but cells were also able to penetrate inside the scaffold of the 70:30 pellets. This finding suggests that the 70:30 ratio had better osteoconduction properties than the 20:80 ratio.
A nearly complete human skeleton dating to the Early Holocene (epi-Paleolithic culture) excavated from Gua Gunung Runtuh, Malaysia, is described. Cranial, dental, and limb bone measurements are recorded on the skeleton, and compared with early and modern skeletal samples from Southeast Asia and Australia. The comparisons demonstrate that the Gua Gunung specimen is most similar to Australian Aborigines in dental and limb measurements, while the cranial measurements indicate a close affinity to Mesolithic samples from Malaysia and Flores. These findings further suggest that the Gua Gunung skeleton, as well as other fossils from Tabon and Niah, are representative of an early group of people who occupied Sundaland during the late Pleistocene, and may be the ancestors of Australian Aborigines. Some of the dental and limb bone measurements exhibited by the ancestors persist in Southeast Asian populations until the early Holocene. Differences in cranial traits have, however, accumulated since the late Pleistocene in Australian Aborigines and early Southeast Asian peoples.
Matched MeSH terms: Bone and Bones/anatomy & histology*
The testosterone deficiency syndrome (TDS) is characterised by numerous symptoms, including low libido, increased fat mass, fatigue, erectile dysfunction or osteoporosis, and up to 80% of men will experience some kind of ageing males' symptoms. This is caused by the age-depending decline in serum testosterone levels with concentrations being about 40-50% lower in men older than 60 years compared with young men. This significant decline in testosterone levels is further closely linked with medical conditions such as obesity, metabolic syndrome, diabetes or hypertension. The conventional way of treating TDS is the testosterone replacement therapy (TRT), for which preparations are on the market. Apart from the beneficial effects of TRT, significant adverse side effects have been described, and prostate cancer (PCa) as absolute contraindication is debated. Eurycoma longifolia (Tongkat Ali; TA) is natural alternative to TRT and has been shown to restore serum testosterone levels, thus significantly improving sexual health. This includes significant positive effects on bone health and physical condition of patients. In addition, a significant antihyperglycaemic effect and cytotoxicity against PCas cells has been shown. Thus far, at therapeutic concentrations, no significant side effects of the treatment were obvious. Therefore, TA might be a safe alternative to TRT.
Understanding the bioelectrical properties of bone tissue is key to developing new treatment strategies for bone diseases and injuries, as well as improving the design and fabrication of scaffold implants for bone tissue engineering. The bioelectrical properties of bone tissue can be attributed to the interaction of its various cell lineages (osteocyte, osteoblast and osteoclast) with the surrounding extracellular matrix, in the presence of various biomechanical stimuli arising from routine physical activities; and is best described as a combination and overlap of dielectric, piezoelectric, pyroelectric and ferroelectric properties, together with streaming potential and electro-osmosis. There is close interdependence and interaction of the various electroactive and electrosensitive components of bone tissue, including cell membrane potential, voltage-gated ion channels, intracellular signaling pathways, and cell surface receptors, together with various matrix components such as collagen, hydroxyapatite, proteoglycans and glycosaminoglycans. It is the remarkably complex web of interactive cross-talk between the organic and non-organic components of bone that define its electrophysiological properties, which in turn exerts a profound influence on its metabolism, homeostasis and regeneration in health and disease. This has spurred increasing interest in application of electroactive scaffolds in bone tissue engineering, to recapitulate the natural electrophysiological microenvironment of healthy bone tissue to facilitate bone defect repair.
Endoseous Implant insertion for the replacement of missing teeth is the state of the art at present times. An understanding of the biology of the perimplant tissues is imperative for the overall success in the dental rehabilitation of a patient with fixture supported prosthesis. The dental implant tissue interface comprises bone, both cortical and cancellous bone; supracrestal connective tissue and the epithelial attachment. A comprehensive review of the response of bone during the postoperative or healing phase, the loading or remodelling phase and during the steady phase is described.
Odontogenic carcinomas of the jaws are subclassified into malignant ameloblastoma, ameloblastic carcinoma and primary intraosseous carcinoma arising from within the bone. These may arise from residual islands of epithelium derived from dental lamina or epithelial lining of dental cysts. Ameloblastic carcinoma is extremely rare. An aggressive case of ameloblastic carcinoma occumng in a 59-year-old Malay man is presented. Wide excision of the primary lesion with radical neck dissection was carried out. He developed lung metastasis 4 months post-operatively. Despite chemotherapy upon discovery of lung metastasis, he expired 7 months following the initial diagnosis.
This systematic review focuses on the management of two types of osseous defects, i.e. dehiscence and fenestration that arise during the placement of dental implant in the edentulous area (delayed implant placement). A systematic online search of main database from 1975 to 2009 was made. Five randomised controlled trials have been identified based on the inclusion criteria. Different management procedures were identified, in which guided bone regeneration procedure was most commonly advocated. Resorbable and non-resorbable m'embranes were compared, in which resorbable membrane was preferred as it caused less complicatiQn of membrane exposure or risk of infection. The benefit of using bone substitute along with membrane in rypairing bony defects cannot be concluded.
Hydroxyapatite (HA) has been increasingly used in biomedical applications due to its biocompatibility with living tissues. However, its use is limited to low load bearing areas due to the poor mechanical properties compared to bone. The aim of this project is to improve the mechanical properties of synthetic HA by optimising the processing method and also by using a phosphate based glass as a sintering aid to develop Glass Reinforced Hydroxyapatite (GR-HA). A phosphate based glass containing CaO, P2O5 and CaF2 was incorporated into HA at 2.5wt% and 5wt% additions during the milling process prior to sintering at 1300°C. The flexural strength mean values for GR-HA ranged from 80MPa to 110MPa. Pure HA exhibited a much lower flexural strength mean value ranging from 66MPa to 79MPa. The improved mechanical properties were associated with the occurrence of residual stress as a result of decomposition of HA to b-Tricalcium Phosphate (TCP) and in 5wt% GRHA to a-Tricalcium Phosphate (TCP).
This study evaluated the effectiveness of demineralized freeze-dried bone xenograft in reducing post-surgical pocket depth in moderate to advanced adult periodontitis in patients. Nine patients with a total of eighteen intrabony defects were selected for this study. The bony defects were matched for tooth type, location and pocket depth. Following an initial non-surgical treatment, only pockets of 5 to 7 mm deep were indicated for surgery. Periodontal pockets were measured pre-operatively and at 3, 6 and 9 months post-surgically. The study protocol included a split mouth design, where surgical treatment was carried out at both test and control sites. The test sites were assigned demineralized freeze-dried bone xenograft and the control sites were subjected to debridement alone without the use of demineralized freeze-dried bone xenograft. The results from this study showed a statistically significant difference in the mean pocket depth at 6 and 9 months post-operatively for both test and control groups, but there was no statistically significant difference at 3 months. In conclusion, demineralized freeze-dried bone xenograft was ineffective in reducing periodontal pocket depth in patients with moderate to severe periodontitis, as compared to surgical debridement alone.
Currently many dental implant systems with varied and numerous components are available commercially, and with new implant systems and designs emerging, it is essential that the user understands that any system selected should be based on sound scientific principles and capable of osseoil!tegration. This has been defined in many different ways, with biomaterial, biological and biomechanical factors being the main considerations. The final restoration is based on both biological tissue and mechanical components. As the success of osseointegration is based on the clinical outcome, clinicians must ensure that the stresses that the superstructure, implant, and surrounding bone are subjected to are within the tolerable limits of the various components, even though the degree of tolerance has not yet been fully defined.
The CO2 laser has been actively used clinically for soft tissue surgery. The advantages have been widely acknowledged. In implant related tissue surgery, the use .6f CO2 laser has been debated on whether the heat generated during the procedure would be detrimental to the bone thus losing the implants through disosseointegration. In this preliminary work, CO2 laser was used to perform a simulated gingivectomy of tissue surrounding plasma coated titanium implants. The purpose was to observe the pattern of heat generated at different levels of the implant body. The safe power range and standard precaution was also identified. The results suggested that power output between 6 Watt to 8 Watt in repeated pulsed mode with duration of 5 seconds is considered safe. With this mode the operator
Migration of a foreign body from the hypopharynx to the subcutaneous tissue of the neck is a rare event. We report a case of a 48-year-old male who accidentally swallowed a fish bone which was not identified intraoperatively. The patient then presented with migration of the bone to the soft tissue of the neck. We conclude that careful assessment of the patient with a foreign body in the throat is crucial to avoid fatal complications.
Fatigue assessment of the trabecular bone has been developed to give a better understanding of bone properties. While most fatigue studies are relying on uniaxial compressive load as the method of assessment, in various cases details are missing, or the uniaxial results are not very realistic. In this paper, the effect of three different load histories from physiological loading applied on the trabecular bone were studied in order to predict the first failure surface and the fatigue lifetime. The fatigue behaviour of the trabecular bone under uniaxial load was compared to that of multiaxial load using a finite element simulation. The plastic strain was found localized at the trabecular structure under multiaxial load. On average, applying multiaxial loads reduced more than five times the fatigue life of the trabecular bone. The results provide evidence that multiaxial loading is dominated in the low cycle fatigue in contrast to the uniaxial one. Both bone volume fraction and structural model index were best predictors of failure (p
Matched MeSH terms: Bone and Bones/pathology; Bone and Bones/physiopathology*; Bone and Bones/chemistry*
As drilling generates substantial bone thermomechanical damage due to inappropriate cutting tool selection, researchers have proposed various approaches to mitigate this problem. Among these, improving the drill bit design is one of the most feasible and economical solutions. The theory and applications in drill design have been progressing, and research has been published in various fields. However, pieces of information on drill design are dispersed, and no comprehensive review paper focusing on this topic. Systemizing this information is crucial and, therefore, the impetus of this review. Here, we review not only the state-of-the-art in drill bit designs-advances in surgical drill bit design-but also the influences of each drill bit geometries on bone damage. Also, this work provides future directions for this topic and guidelines for designing an improved surgical drill bit. The information in this paper would be useful as a one-stop document for clinicians, engineers, and researchers who require information related to the tool design in bone drilling surgery.
Matched MeSH terms: Bone and Bones/injuries; Bone and Bones/surgery*
Osteoporosis, a degenerative bone disease, is characterized by low bone mass and microstructural deterioration of bone tissue resulting in aggravated bone fragility and susceptibility to fractures. The trend of extended life expectancy is accompanied by a rise in the prevalence of osteoporosis and concomitant complications in the elderly population. Epidemiological evidence has shown an association between vitamin E consumption and the prevention of age-related bone loss in elderly women and men. Animal studies show that ingestion of vitamin E, especially tocotrienols, may benefit bone health in terms of maintaining higher bone mineral density and improving bone microstructure and quality. The beneficial effects of tocotrienols on bone health appear to be mediated via antioxidant/anti-inflammatory pathways and/or 3-hydroxy-3-methylglutaryl coenzyme A mechanisms. We discuss (1) an overview of the prevalence and etiology of osteoporosis, (2) types of vitamin E (tocopherols versus tocotrienols), (3) findings of tocotrienols and bone health from published in vitro and animal studies, (4) possible mechanisms involved in bone protection, and (5) challenges and future direction for research.
Matched MeSH terms: Bone and Bones/drug effects; Bone and Bones/pathology; Bone and Bones/physiology
Fishbones are of particular interest to otolaryngologists. Most fishbones can be removed transorally or via endoscopic guidance. Transcervical neck exploration is occasionally necessary, especially in cases of an embedded foreign body. Computed tomography is the most sensitive and specific imaging modality for identifying embedded fishbones. To our knowledge, this is the first reported case of a laryngeal foreign body embedded in the paraglottic space that was removed using an open approach via a lateral thyroid cartilage window.