A method of treating an apical root fracture with accompanying resorption at the junction of the fracture fragments using glass-cermet cement is described. Endodontically, the material had previously been used for repair of lateral resorptive root defects and retrograde root fillings. Complete bone regeneration was observed three years post-operatively following treatment of the root fracture in the conventional manner. The various advantages of glass-cermet cement as a root filling material used in the technique described are discussed.
The strategy used to generate tissue-engineered bone construct, in view of future clinical application is presented here. Osteoprogenitor cells from periosteum of consenting scoliosis patients were isolated. Growth factors viz TGF-B2, bFGF and IGF-1 were used in concert to increase cell proliferation during in vitro cell expansion. Porous tricalcium phosphate (TCP)-hydroxyapatite (HA) scaffold was used as the scaffold to form 3D bone construct. We found that the addition of growth factors, greatly increased cell growth by 2 to 7 fold. TCP/HA proved to be the ideal scaffold for cell attachment and proliferation. Hence, this model will be further carried out on animal trial.
The standard bioglass composition GS45 as well as with excess silica GS50 or with the addition of 5% titanium oxide GS45+Ti5, were prepared by the polymeric route. The different glass components were added to the formed polymer. Firing at 700 degrees C gave an amorphous product with microporous texture that readily crystallizes out at 900 degrees C. The prepared materials were highly porous with two modes of pore system micro-pores and macro-pores with a size ranging between 100 microm to 0.006 microm and a porosity reaching 73%. The measured bulk density was between 0.36 to 1.1g/cm3. The fired material preserved the former structure of the polymer precursor. Biocompatibility was verified in vitro and vivo. IR of the specimens previously immersed in SBF revealed the formation of apatite like layer. While the histology sections of implants in rate femurs showed new bone tissue or bone trabeculae after 21 days.
Bone marrow stem cells (BMSC), known for its multipotency to differentiate into various mesenchymal cells such as chodrocyte, osteoblasts, adipocytes, etc, have been actively applied in tissue engineering. BMSC have been successfully isolated from bone marrow aspirate and bone marrow scraping from patients of various ages (13-56 years) with as little as 2ml to 5ml aspirate. BMSC isolated from our laboratory showed the presence of a heterogenous population that showed varying prevalence of surface antigens and the presence of telomerase activity albeit weak. Upon osteogenic induction, alkaline phosphatase activity and mineralization activity were observed.
Porous calcium phosphate ceramics have found enormous use in biomedical applications including bone tissue regeneration, cell proliferation, and drug delivery. In bone tissue engineering it has been applied as filling material for bone defects and augmentation, artificial bone graft material, and prosthesis revision surgery. Their high surface area leads to excellent osteoconductivity and resorbability providing fast bone ingrowths. Porous calcium phosphate can be produced by a variety of methods. This paper discusses briefly fundamental aspects of porous calcium phosphate for biomedical applications as well as various techniques used to prepare porous calcium phosphate.
The purpose of this study was to compare bone healing and coronal bone remodeling following both immediate and delayed placement of titanium dental implants in extraction sockets.
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.
The use of bone grafts in treating non- or delayed unions as the result of large bone loss is well established. However, despite good outcomes, the time to achieve complete union is still considerably long. To overcome this problem, the use of platelet-rich plasma (PRP) has been advocated albeit with varying success. To determine the true effectiveness of PRP in treating non-/delayed unions, a study was conducted using (n=12) rabbit models.
This review summarises the major developments of macroporous bioceramics used mainly for repairing bone defects. Porous bioceramics have been receiving attention ever since their larger surface area was reported to be beneficial for the formation of more rigid bonds with host tissues. The study of porous bioceramics is important to overcome the less favourable bonds formed between dense bioceramics and host tissues, especially in healing bone defects. Macroporous bioceramics, which have been studied extensively, include hydroxyapatite, tricalcium phosphate, alumina, and zirconia. The pore size and interconnections both have significant effects on the growth rate of bone tissues. The optimum pore size of hydroxyapatite scaffolds for bone growth was found to be 300 µm. The existence of interconnections between pores is critical during the initial stage of tissue ingrowth on porous hydroxyapatite scaffolds. Furthermore, pore formation on β-tricalcium phosphate scaffolds also allowed the impregnation of growth factors and cells to improve bone tissues growth significantly. The formation of vascularised tissues was observed on macroporous alumina but did not take place in the case of dense alumina due to its bioinert nature. A macroporous alumina coating on scaffolds was able to improve the overall mechanical properties, and it enabled the impregnation of bioactive materials that could increase the bone growth rate. Despite the bioinertness of zirconia, porous zirconia was useful in designing scaffolds with superior mechanical properties after being coated with bioactive materials. The pores in zirconia were believed to improve the bone growth on the coated system. In summary, although the formation of pores in bioceramics may adversely affect mechanical properties, the advantages provided by the pores are crucial in repairing bone defects.
The purpose of the study was to evaluate radiologically the efficacy of guided bone regeneration using composite bone graft (autogenous bone graft and anorganic bovine bone graft [Bio-Oss]) along with resorbable collagen membrane (BioMend Extend) in the augmentation of Seibert's class I ridge defects in maxilla. Bone width was evaluated using computerized tomography at day 0 and at day 180 at 2 mm, 4 mm, and 6 mm from the crest. There was a statistically significant increase in bone width between day 0 and day 180 at 2 mm, 4 mm, and 6 mm from the crest. The results of the study demonstrated an increase in bone width of Seibert's class I ridge defects in the maxilla of the study patients.
The main aim of the present study was to evaluate the capacity of stem cells from human exfoliated deciduous teeth (SHED) to enhance mandibular distraction osteogenesis (DO) in rabbits.
Hydroxyapatite is a biocompatible material that is extensively used in the replacement and regeneration of bone material. In nature, nanostructured hydroxyapatite is the main component present in hard body tissues. Hence, the state of the art in nanotechnology can be exploited to synthesize nanophase hydroxyapatite that has similar properties with natural hydroxyapatite. Sustainable methods to mass-produce synthetic hydroxyapatite nanoparticles are being developed to meet the increasing demand for these materials and to further develop the progress made in hard tissue regeneration, especially for orthopedic and dental applications. This article reviews the current developments in nanophase hydroxyapatite through various manufacturing techniques and modifications.
Introduction: Stem cells from human exfoliated deciduous teeth (SHED) are highly proliferative, clonogenic cells capable of differentiating into osteoblasts and inducing bone formation. It is a potential alternative for stem cell bone regeneration therapy. However, stem cell therapy carries the risk of immune rejection mediated by inflammatory cytokines of the human defense system. Objective: This preliminary research studies the interaction between SHED and the immune system by determining the inflammatory cytokines profile and osteogenic potential of SHED. Methods: Human fetal osteoblasts (hFOb) cell line and isolated SHED were cultured and total RNA was extracted, followed by reverse transcription cDNA synthesis. Semi-quantitative reverse transcription PCR and Multiplex PCR were performed to detect the expression levels of OPG/RANKL and TNF-α, IL-1β, IL-6, IL-8 and TGF-β in both cell types. Results: Analysis showed that SHED expressed significantly lower amounts of IL-1β, IL-6, and IL-8 compared to hFOB. IL-1β is a potent bone-resorbing factor, while IL-6 and IL-8 induce osteoclastogenesis and osteolysis respectively. SHED did not express TNF-α which stimulates osteoclastic activity. SHED demonstrated high OPG/RANKL ratio, in contrast with that of marrow stem cells described in previous studies. Our findings suggest that SHED may have improved immunomodulatory profile in terms of promoting relatively lower inflammatory reaction during transplant and enhancing bone regeneration. Conclusion: SHED has a potential to be a good source of osteoblasts for bone regeneration therapy. Further studies on the immunomodulatory properties of SHED-derived osteoblasts are necessary to enable stem cell therapy in immunocompetent hosts.
The large surface area of highly porous titanium structures produced by additive manufacturing can be modified using biofunctionalizing surface treatments to improve the bone regeneration performance of these otherwise bioinert biomaterials. In this longitudinal study, we applied and compared three types of biofunctionalizing surface treatments, namely acid-alkali (AcAl), alkali-acid-heat treatment (AlAcH), and anodizing-heat treatment (AnH). The effects of treatments on apatite forming ability, cell attachment, cell proliferation, osteogenic gene expression, bone regeneration, biomechanical stability, and bone-biomaterial contact were evaluated using apatite forming ability test, cell culture assays, and animal experiments. It was found that AcAl and AnH work through completely different routes. While AcAl improved the apatite forming ability of as-manufactured (AsM) specimens, it did not have any positive effect on cell attachment, cell proliferation, and osteogenic gene expression. In contrast, AnH did not improve the apatite forming ability of AsM specimens but showed significantly better cell attachment, cell proliferation, and expression of osteogenic markers. The performance of AlAcH in terms of apatite forming ability and cell response was in between both extremes of AnH and AsM. AcAl resulted in significantly larger volumes of newly formed bone within the pores of the scaffold as compared to AnH. Interestingly, larger volumes of regenerated bone did not translate into improved biomechanical stability as AnH exhibited significantly better biomechanical stability as compared to AcAl suggesting that the beneficial effects of cell-nanotopography modulations somehow surpassed the benefits of improved apatite forming ability. In conclusion, the applied surface treatments have considerable effects on apatite forming ability, cell attachment, cell proliferation, and bone ingrowth of the studied biomaterials. The relationship between these properties and the bone-implant biomechanics is, however, not trivial.
Matched MeSH terms: Bone Regeneration/drug effects*
This paper discusses the successful fabrication of a novel triple-layered poly(lactic-co-glycolic acid) (PLGA)-based composite membrane using only a single step that combines the techniques of solvent casting and thermally induced phase separation/solvent leaching. The resulting graded membrane consists of a small pore size layer-1 containing 10 wt% non-stoichiometric nanoapatite (NAp)+1-3 wt% lauric acid (LA) for fibroblastic cell and bacterial inhibition, an intermediate layer-2 with 20-50 wt% NAp+1 wt% LA, and a large pore size layer-3 containing 30-100 wt% NAp without LA to allow bone cell growth. The synergic effects of 10-30 wt% NAp and 1 wt% LA in the membrane demonstrated higher tensile strength (0.61 MPa) and a more elastic behavior (16.1% elongation at break) in 3 wt% LA added membrane compared with the pure PLGA (0.49 MPa, 9.1%). The addition of LA resulted in a remarkable plasticizing effect on PLGA at 3 wt% due to weak intermolecular interactions in PLGA. The pure and composite PLGA membranes had good cell viability toward human skin fibroblast, regardless of LA and NAp contents.