Osseointegrated transcutaneous implants could provide an alternative and improved means of attaching artificial limbs for amputees,however epithelial down growth,inflammation,and infections are common failure modaliti...Osseointegrated transcutaneous implants could provide an alternative and improved means of attaching artificial limbs for amputees,however epithelial down growth,inflammation,and infections are common failure modalities associated with their use.To overcome these problems,a tight seal associated with the epidermal and dermal adhesion to the implant is crucial.This could be achieved with specific biomaterials(that mimic the surrounding tissue),or a tissue-specific design to enhance the proliferation and attachment of dermal fibroblasts and keratinocytes.The intraosseous transcutaneous amputation prosthesis is a new device with a pylon and a flange,which is specifically designed for optimising soft tissue attachment.Previously the flange has been fabricated using traditional machining techniques,however,the advent of additive layer manufacturing(ALM)has enabled 3-dimensional porous flanges with specific pore sizes to be used to optimise soft tissue integration and reduce failure of osseointegrated transcutaneous implants.The study aimed to investigate the effect of ALM-manufactured porous flanges on soft tissue ingrowth and attachment in an in vivo ovine model that replicates an osseointegrated percutaneous implant.At 12 and 24 weeks,epithelial downgrowth,dermal attachment and revascularisation into ALM-manufactured flanges with three different pore sizes were compared with machined controls where the pores were made using conventional drilling.The pore sizes of the ALM flanges were 700,1000 and 1250μm.We hypothesised that ALM porous flanges would reduce downgrowth,improve soft tissue integration and revascularisation compared with machined controls.The results supported our hypothesis with significantly greater soft tissue integration and revascularisation in ALM porous flanges compared with machined controls.展开更多
Medical modeling and 3-dimensional(3D)virtual surgical planning represent a rapidly expanding,technological advancement especially useful in complex mandibular or maxillary defects in head and neck reconstruction.With...Medical modeling and 3-dimensional(3D)virtual surgical planning represent a rapidly expanding,technological advancement especially useful in complex mandibular or maxillary defects in head and neck reconstruction.With utilization of 3D surgical planning,the reconstructive surgeon can initiate dental rehabilitation during the primary surgery with osseointegrated implants(OI),streamlining a typically lengthy process to full oral rehabilitation.Careful patient selection is important to optimize outcomes with immediate OI,and factors to consider during the evaluation process include pathology,prognosis,anticipated defect,dental status,donor site availability,and patient motivation and resources.Synthesizing this information and developing a reconstructive plan with a multidisciplinary team approach is critical to expedite dental rehabilitation for select patients.A review of relevant literature and our surgical planning algorithm for selecting candidates for immediate OI is provided,along with our experience using this decision algorithm in a uniquely complex clinical case.展开更多
Aim:Ovine models for osseointegrated prosthetics research are well established,but do not consider neural control of advanced prostheses.The validity of interfacing technologies,such as the Osseointegrated Neural Inte...Aim:Ovine models for osseointegrated prosthetics research are well established,but do not consider neural control of advanced prostheses.The validity of interfacing technologies,such as the Osseointegrated Neural Interface(ONI),in their ability to provide communication between native nerves and advanced prosthetics is required,necessitating a stable,longitudinal large animal model for testing.The objective of this study is to provide a detailed anatomic description of the major nerves distal to the carpal and tarsal joints,informing the creation of a chronic ONI for prosthetic control in sheep.Methods:Six pelvic and six thoracic cadaveric limbs from mature female,non-lactating sheep were utilized.Radiographs were obtained to determine average bone length,medullary canal diameter,and cortical bone thickness.Microsurgical dissection was performed to discern topographical neuroanatomy and average circumferences of the major nerves of the pelvic and thoracic limbs.Histologic analysis was performed.A surgical approach for the creation of ONI was designed.Results:Average metacarpal and metatarsal length was 15.0 cm(±0.0)and 19.7 cm(±1.0),respectively.Average intramedullary canal diameter was 12.91 mm(±3.69)for forelimbs and 12.60 mm(±3.69)for hindlimbs.The thoracic limb nerves consisted of one dorsal and three ventral nerves,with an average circumference of 5.14 mm(±2.00)and 5.05 mm(±1.06),respectively.Pelvic limb nerves consisted of two dorsal and one ventral nerve with an average circumference of 6.27 mm(±1.79)and 5.40 mm(±0.53),respectively.Conclusions:These anatomic data inform the surgical approach and manufacture of a sensory ONI for chronic testing in awake,freely ambulating animals for future clinical translation.展开更多
The poor surface conditions and osseointegration capacity of 3D printed Ti6Al4V implants(3DPT)significantly influence their performance as orthopedic and dental implants.In this work,we creatively introduce a one-step...The poor surface conditions and osseointegration capacity of 3D printed Ti6Al4V implants(3DPT)significantly influence their performance as orthopedic and dental implants.In this work,we creatively introduce a one-step femtosecond laser treatment to improve the surface conditions and osteointegration.The surface characterization,mechanical properties,corrosion resistance,and biological responses were investigated.These results found that femtosecond laser eliminated defects like embedded powders and superficial cracks while forming the nano cones-like structures surface on 3DPT,leading to enhanced osseointegration,anti-corrosion,and anti-fatigue performance.Molecular dynamics simulations revealed the ablation removal mechanism and the formation of nano cone-like structures.These findings were further supported by the in vivo studies,showing that the FS-treated implants had superior bone-implant contact and osseointegration.Hence,the one-step femtosecond laser method is regarded as a promising surface modification method for improving the functional performance of Ti-based orthopedic implants.展开更多
Polyetheretherketone(PEEK)is a desirable candidate to replace conventional metal implants owing to its excellent mechanical properties.However,the intrinsic bioinertness of PEEK results in inferior or delayed osseoint...Polyetheretherketone(PEEK)is a desirable candidate to replace conventional metal implants owing to its excellent mechanical properties.However,the intrinsic bioinertness of PEEK results in inferior or delayed osseointegration,which limits its further clinical application.To address these challenges,one leading strategy is to construct a biofunctionalized surface on PEEK that provides a coordinated osteoblastosteoclast interactions microenvironment.Herein,alendronate(ALN),a common bone absorption inhibitor,was loaded in biomedical inorganic/organic microspheres,consisting of bioactive inorganic nanohydroxyapatite core,and chitosan(CS)shell.Polydopamine(PDA)modification was employed to ensure the adherence of the microspheres to the PEEK surface.The delivery of ALN and Ca^(2+)from these microspheres simultaneously suppressed osteoclastogenesis and promoted osteogenesis,resulting in a coordinated cascade of osteoblast-osteoclast interactions crucial for the per-implant osseointegration.In vitro experiments demonstrated that the PEEK surface exhibited satisfactory biocompatibility and enhanced the proliferation and osteogenic differentiation of rat bone mesenchymal stem cells while inhibiting the osteoclast differentiation.Moreover,the in vivo rat femoral drilling model demonstrated superior osseointegration three months after implantation.By considering the bone remodeling processes,this study proposes a novel biofunctionalized PEEK surface that regulates the activities of both osteoblasts and osteoclasts to promote osseointegration.展开更多
The remodeling of macrophages mediated by biomaterials is an important step in osseointegration.The biointerfacial characteristics shaped by implants and the bioenergetic state derived from macrophages are considered ...The remodeling of macrophages mediated by biomaterials is an important step in osseointegration.The biointerfacial characteristics shaped by implants and the bioenergetic state derived from macrophages are considered the key to macrophage reprogramming.In this study,the integrated Ti/Zn composites with optimized morphology and bioactive phase were prepared by friction stir processing,which could meet the multi-biofunctional requirements in the application of narrow-diameter implants.The severe plastic deformation and the hindrance of Zn particles to grain growth promote grain refinement,resulting in enhanced mechanical properties.The cell interfacial adhesion mediated by the grain boundary collaborated the energy metabolism reprogramming induced by the released Zn ion,promoting jointly anti-inflammatory cascade in macrophages and favorable osteogenesis in bone marrow mesenchymal stem cells(BMSCs).This study provides a new simultaneous approach of morphology and composition modification for titanium implants,and reveals the important role of grain size and bioactive element in the reversion of macrophage fate as well.展开更多
Large bone defects in load-bearing bone can result from tumor resection,osteomyelitis,trauma,and other factors.Although bone has the intrinsic potential to self-repair and regenerate,the repair of large bone defects w...Large bone defects in load-bearing bone can result from tumor resection,osteomyelitis,trauma,and other factors.Although bone has the intrinsic potential to self-repair and regenerate,the repair of large bone defects which exceed a certain critical size remains a substantial clinical challenge.Traditionally,repair methods involve using autologous or allogeneic bone tissue to replace the lost bone tissue at defect sites,and autogenous bone grafting remains the“gold standard”treatment.However,the application of traditional bone grafts is limited by drawbacks such as the quantity of extractable bone,donor-site morbidities,and the risk of rejection.In recent years,the clinical demand for alternatives to traditional bone grafts has promoted the development of novel bone-grafting substitutes.In addition to osteoconductivity and osteoinductivity,optimal mechanical properties have recently been the focus of efforts to improve the treatment success of novel bone-grafting alternatives in load-bearing bone defects,but most biomaterial synthetic scaffolds cannot provide sufficient mechanical strength.A fundamental challenge is to find an appropriate balance between mechanical and tissue-regeneration requirements.In this review,the use of traditional bone grafts in load-bearing bone defects,as well as their advantages and disadvantages,is summarized and reviewed.Furthermore,we highlight recent development strategies for novel bone grafts appropriate for load-bearing bone defects based on substance,structural,and functional bionics to provide ideas and directions for future research.展开更多
Mechanical loading constitutes a fundamental determinant in the process of bone remodeling.This modeling encompasses the incorporation of mechanical stimuli,the involvement of cellular and molecular constituents,as we...Mechanical loading constitutes a fundamental determinant in the process of bone remodeling.This modeling encompasses the incorporation of mechanical stimuli,the involvement of cellular and molecular constituents,as well as the utilization of sophisticated computational methodologies.Such an approach is imperative for forecasting bone behaviour across varying environmental conditions.In the present study,key findings from bone mechanobiology are reviewed,along with the possibility that Functionally Graded Materials(FGM)enhances osseointegration and lowers the stress-shielding effect during bone remodeling and compared to titanium,FGM improves periprosthetic bone remodeling.To summarise some of the most important findings from computational models of bone mechanobiology,explaining how modifications to the mechanical environment affect implant design,growth of bone,and bone response.The impact that changes related to the mechanical environment have on bone response is examined using computational models and methods such as surface microtopography to determine how an implant’s bone density has increased over time.This review focuses on the refinement of advanced simulation frameworks and their synergy with imaging technologies to strengthen model validation,ultimately resulting in better clinical outcomes in the context of bone health treatments.展开更多
Spinal fusion is a commonly used technique to treat acute and chronic spinal diseases by fusion of the adjacent vertebrae, aiming at achieving stability and eliminating the mobility of the objective segment. While bon...Spinal fusion is a commonly used technique to treat acute and chronic spinal diseases by fusion of the adjacent vertebrae, aiming at achieving stability and eliminating the mobility of the objective segment. While bone autografts and allografts have been conventionally used for spinal fusion, limitations persist in achieving optimization of both good osteoinductive capacity and mechanical stability. In this study, additively manufactured Zn-Li scaffolds were developed and evaluated for their potential in spinal fusion. First, three scaffold structures (BCC, Diamond, and Gyroid) were designed and verified in vitro. Due to the smooth transition surfaces and uniform degradation behavior, the Gyroid Zn-Li scaffold demonstrated mechanical integrity during degradation and enhanced cellular proliferation compared to the other two scaffolds. Subsequently, Zn-Li scaffolds (Gyroid) were selected for posterolateral lumbar fusion (L4/L5) in rabbits. Following 12 weeks of implantation, the Zn-Li scaffolds demonstrated a moderate biodegradation rate and satisfactory biocompatibility. Compared to bone allografts, the Zn-Li scaffolds significantly improved osseointegration adjacent to the transverse processes, which led to enhanced segmental stability of the fused vertebrae post posterolateral lumbar fusion. Overall, the results show that the biodegradable Zn-Li scaffold holds substantial potential as the next-generation graft for spinal fusion.展开更多
The pore structure of porous scaffolds plays a crucial role in bone repair.The prevalent bone implant structure in clinical practice is the traditional cubic structure.However,the traditional cubic structure exhibits ...The pore structure of porous scaffolds plays a crucial role in bone repair.The prevalent bone implant structure in clinical practice is the traditional cubic structure.However,the traditional cubic structure exhibits sharp edges and junctions that are not conducive to cell adhesion or growth.In this study,a double gyroid(DG)Ti6Al4V scaffold based on a triply periodic minimal surface(TPMS)structure was devised,and the osseointegration performance of DG structural scaffolds with varying porosities was investigated.Compression tests revealed that the elastic modulus and compressive strength of DG structural scaffolds were sufficient for orthopedic implants.In vitro cellular experiments demonstrated that the DG structure significantly enhanced cell proliferation,vascularization,and osteogenic differentiation compared to the cubic structure.The DG structure with 55%porosity exhibited the most favorable outcomes.In vivo experiments in rabbits further demonstrated that DG scaffolds could promote neovascularization and bone regeneration and maturation;those with 55%porosity performed best.Comparing the surface area,specific surface area per unit volume,and internal flow distribution characteristics of gyroid and DG structure scaffolds,the latter are more conducive to cell adhesion and growth within scaffolds.This study underscored the potential of DG scaffolds based on the TPMS structure in optimizing the pore structure design of titanium scaffolds,inducing angiogenesis,and advancing the clinical application of titanium scaffolds for repairing bone defects.展开更多
In clinical settings,tantalum(Ta)is extensively implemented as a bone implant material.Ta is highly stable and biocompatible in vivo,being one of the metallic biomaterials having high affinity for bone tissue.However,...In clinical settings,tantalum(Ta)is extensively implemented as a bone implant material.Ta is highly stable and biocompatible in vivo,being one of the metallic biomaterials having high affinity for bone tissue.However,since Ta is a refractory metal,its application as bone implant material is limited.Most recently,additive manufacturing technology has introduced a novel approach to producing Ta implants.The present study compared the microstructure,surface and mechanical characteristics,and in vitro and in vivo biological characteristics of selective laser melted Ta(SLM Ta),selective laser melted titanium alloy Ti6Al4V with Ta coating(SLM Ti6Al4V with Ta coating),and selective laser melted Ti6Al4V(SLM Ti6Al4V).Results indicate that SLM Ta possesses superior mechanical characteristics contrasted with SLM Ti6Al4V and SLM Ti6Al4V with Ta coating.Furthermore,SLM Ta has anti-inflammatory activity,excellent osseointegration performance,and osteogenic bioactivity.We fabricated an SLM porous Ta bone plate and employed it for internal fixation of ulnar and radius fractures,which has been known to promote fracture healing.Further,the SLM porous Ta bone plate could form an integrated bone plate structure with the bone tissue at the implant site.Afterward,the porous structure of the plate minimizes its elastic modulus and eliminates stress shielding,leaving no need for further surgical removal.In conclusion,the SLM porous Ta bone plate meets the performance requirements(stimulating bone regeneration,non-stress shelter,and no need for second surgery)of an ideal bone plate and may revolutionize the field of internal fixation bone plates for fractures.展开更多
The effects of surface-modified porous titanium implants with different porosities and pore sizes on osseointegration were investigated in vivo.Three porous titanium implants(A30,A40 and A50 containing volume fraction...The effects of surface-modified porous titanium implants with different porosities and pore sizes on osseointegration were investigated in vivo.Three porous titanium implants(A30,A40 and A50 containing volume fractions of space-holder NaCl being 30%,40%and 50%,respectively)were manufactured by metal injection moulding(MIM).The surface-modified implants were implanted into muscles and femurs of hybrid male dogs.Interface osteogenic activity and histological bone ingrowth of porous titanium implants were evaluated at 28,56 and 84 d.The results showed that when additive space-holder amount of NaCl increased from 30%to 50%(volume fraction),the general porosity and mass fraction of macropores of porous titanium rose from 42.4%to 62.0%and from 8.3%to 69.3%,respectively.Histologic sections and fluorescent labeling showed that the A50 implant demonstrated a significantly higher osteogenic capacity at 28 d than other implants.Bone ingrowth into the A30 implant was lower than that into other implants at 84 d.Therefore,the pore structure of A50 implant was suitable for new bone tissue to grow into porous implant.展开更多
Chronic kidney disease （CKD） is a worldwide public health problem that is growing in prevalence and is associated with severe complications. During the progression of the disease, a majority of CKD patients suffer o...Chronic kidney disease （CKD） is a worldwide public health problem that is growing in prevalence and is associated with severe complications. During the progression of the disease, a majority of CKD patients suffer oral complications. Dental implants are currently the most reliable and successful treatment for missing teeth. However, due to complications of CKD such as infections, bone lesions, bleeding risks, and altered drug metabolism, dental implant treatment for renal failure patients on dialysis is more challenging. In this review, we have summarized the characteristics of CKD and previous publications regarding dental treatments for renal failure patients. In addition, we discuss our recent research results and clinical experience in order to provide dental implant practitioners with a clinical guideline for dental implant treatment for renal failure patients undergoing hemodialysis.展开更多
Objective:The purpose of this study was to investigate the effects of a zinc-substituted nano-hydroxyapatite(Zn-HA) coating,applied by an electrochemical process,on implant osseointegraton in a rabbit model.Methods:A ...Objective:The purpose of this study was to investigate the effects of a zinc-substituted nano-hydroxyapatite(Zn-HA) coating,applied by an electrochemical process,on implant osseointegraton in a rabbit model.Methods:A Zn-HA coating or an HA coating was deposited using an electrochemical process.Surface morphology was examined using field-emission scanning electron microscopy.The crystal structure and chemical composition of the coatings were examined using an X-ray diffractometer(XRD) and Fourier transform infrared spectroscopy(FTIR).A total of 78 implants were inserted into femurs and tibias of rabbits.After two,four,and eight weeks,femurs and tibias were retrieved and prepared for histomorphometric evaluation and removal torque(RTQ) tests.Results:Rod-like HA crystals appeared on both implant surfaces.The dimensions of the Zn-HA crystals seemed to be smaller than those of HA.XRD patterns showed that the peaks of both coatings matched well with standard HA patterns.FTIR spectra showed that both coatings consisted of HA crystals.The Zn-HA coating significantly improved the bone area within all threads after four and eight weeks(P<0.05),the bone to implant contact(BIC) at four weeks(P<0.05),and RTQ values after four and eight weeks(P<0.05).Conclusions:The study showed that an electrochemically deposited Zn-HA coating has potential for improving bone integration with an implant surface.展开更多
Three-dimensional-printed(3 D-P)titanium implants display many advantages,such as design flexibility,higher efficiency,the capability to easily construct complex or customized structures,etc.,and is believed to potent...Three-dimensional-printed(3 D-P)titanium implants display many advantages,such as design flexibility,higher efficiency,the capability to easily construct complex or customized structures,etc.,and is believed to potentially replace traditional implants.However,the biological performance of the 3 D-P titanium surface has not been investigated systematically.Herein,we analyzed the surface characteristics of 3 D-P Ti6 Al4 V implants and evaluated the biological responses of bone marrow derived mesenchymal stromal cells(BMSCs)to the 3 D-P surface in vitro.Moreover,after implantation into the rat femoral condyle for3 and 6 weeks,the osseointegration performance was evaluated.The results showed the 3 D-P Ti6 Al4 V implant presented distinct fluctuant macroscale rough surface and relatively better hydrophilicity which enhanced the adhesion,proliferation,osteogenic differentiation and angiogenetic factor expression of BMSCs.Moreover,the in vivo osseointegration performance was also better than that of the control group at the early stage.The present study suggested the 3 D-P titanium alloy is a promising candidate to be used as implant material.展开更多
Cu has been proved to possess various beneficial biological activities, while sandblasting and acid etching(SLA) is widely used to modify the commercial dental implant in order to improve osseointegration. Based on th...Cu has been proved to possess various beneficial biological activities, while sandblasting and acid etching(SLA) is widely used to modify the commercial dental implant in order to improve osseointegration. Based on the above, a novel antimicrobial dental implant material, Ti-Cu alloy, was treated with SLA, to combine chemical design(Cu addition) and topographical modification(SLA). In this work, the effects of SLA treated Ti-Cu alloys(Ti-Cu/SLA) on osteogenesis, angiogenesis and antibacterial properties were evaluated from both in vitro and in vivo tests, and Ti/SLA and Ti-Cu(without SLA) were served as control groups. Benefiting by the combined effects of chemical design(Cu addition) and micro-submicron hybrid structures(SLA),Ti-Cu/SLA had significantly improved inhibitory effects on oral anaerobic bacteria(P. gingivalis and S.mutans) and could induce upregulation of osteogenic-related and angiogenic-related genes expression in vitro. More importantly, in vivo studies also demonstrated that Ti-Cu/SLA implants had wonderful biological performance. In the osseointegration model, Ti-Cu/SLA implant promoted osseointegration via increasing peri-implant bone formation and presenting good bone-binding, compared to Ti/SLA and Ti-Cu implants. Additionally, in the peri-implantitis model, Ti-Cu/SLA effectively resisted the bone resorption resulted from bacterial infection and meanwhile promoted osseointegration. All these results suggest that the novel multiple functional Ti-Cu/SLA implant with rapid osseointegration and bone resorption inhibition abilities has the potential application in the future dental implantation.展开更多
AIM: To assess the failure and bone-to-implant contact rate of dental implants placed on osteoporotic subjects. METHODS: Extensive examination strategies were created to classify studies for this systematic review. ME...AIM: To assess the failure and bone-to-implant contact rate of dental implants placed on osteoporotic subjects. METHODS: Extensive examination strategies were created to classify studies for this systematic review. MEDLINE(via Pub Med) and EMBASE database were examined for studies in English up to and including May 2014. The examination presented a combination of the MeS H words described as follow: "osteoporosis" or "osteopenia" or "estrogen deficiency" AND "implant" or "dental implant" or "osseointegration". Assessment of clinical and/or histological peri-implant conditions in osteoporosis subjects treated with titanium dental implants. The examination included a combination of the MeS H terms described as follow: "osteoporosis" or "osteopenia" or "estrogen deficiency" AND "implant" or "dental implant" or "osseointegration".RESULTS: Of 943 potentially eligible articles, 12 were included in the study. A total of 133 subjects with osteoporosis, 73 subjects diagnosed with osteopenia and 708 healthy subjects were assessed in this systematic review. In these subjects were installed 367, 205, 2981 dental implants in osteoporotic, osteopenic and healthy subjects, respectively. The failure rate of dental implant was 10.9% in osteoporotic subjects, 8.29% in osteopenic and 11.43% in healthy ones. Bone-to-implant contact obtained from retrieved implants ranged between 49.96% to 47.84%, for osteoporosis and non-osteoporotic subjects. CONCLUSION: Osteoporotic subjects presented higher rates of implant loss, however, there is a lower evidence to strengthen or refute the hypothesis that osteoporosis may have detrimental effects on bone healing. Consequently, final conclusions regarding the effect of osteoporosis in dental implant therapy cannot be made at this time. There are no randomized clinical trial accessible for evaluation and the retrospectivenature of the evaluated studies shall be taken in account when interpreting this study.展开更多
Titanium(Ti)and titanium alloys have become widely used as biomedical materials in orthopedics because of their good machinability,corrosion resistance,low elastic modulus and excellent biocompatibility.However,when T...Titanium(Ti)and titanium alloys have become widely used as biomedical materials in orthopedics because of their good machinability,corrosion resistance,low elastic modulus and excellent biocompatibility.However,when Ti-based implants are used for bone repair and replacement,they are easy to cause bacteria adhesion and aggregation,which leads to postoperative infection.In addition,Ti and its alloys,as bio-inert materials,cannot induce desirable tissue responses such as osseointegration after implantation,which will eventually lead to implant loosening.Postoperative bacterial infection and lack of osseointegration directly lead to the failure of implantation surgery and are not conductive to the long-term service of titanium-based implants.Recently,researchers have made many attempts to focus on the surface modification of multifunctional Ti-based implants to endow them with both antibacterial activity and simultaneous osteoinductive property.In this review,we primarily highlighted the recent progresses in the surface design of Ti implants with both antimicrobial and osteoinductive properties for orthopedic applications.First,the challenges for treating implant-associated infections were briefly introduced such as the emergence of antibiotic resistance,the formation of biofilms,and the construction of cell-selective surfaces.Some of the essential fundamentals were concisely introduced to address these emerging challenges.Next,we intended to elaborate the potential strategies of multifunctional surface design to endow good osseointegration for antibacterial Ti implants and highlighted the recent advances of the implants.We hope that this review will provide theoretical basis and technical support for the development of new Ti implant with antibacterial and osteogenic functions.展开更多
Additive manufacturing of porous, open-cellular metal or alloy implants, fabricated by laser or electron beam melting of a powder bed, is briefly reviewed in relation to optimizing biomechanical compatibility by assur...Additive manufacturing of porous, open-cellular metal or alloy implants, fabricated by laser or electron beam melting of a powder bed, is briefly reviewed in relation to optimizing biomechanical compatibility by assuring elastic(Young's) modulus matching of proximate bone, along with corresponding pore sizes assuring osseointegration and vasculature development and migration. In addition, associated, requisite compressive and fatigue strengths for such implants are described. Strategies for optimizing osteoblast(bone cell) development and osteoinduction as well as vascularization of tissue in 3 D scaffolds and tissue engineering constructs for bone repair are reviewed in relation to the biology of osteogenesis and neovascularization in bone, and the role of associated growth factors, bone morphogenic proteins, signaling molecules and the like. Prospects for infusing hydrogel/collagen matrices containing these cellular and protein components or surgically extracted intramedullary(bone marrow) concentrate/aspirate containing these biological and cell components into porous implants are discussed, as strategies for creating living implants, which over the long term would act as metal or alloy scaffolds.展开更多
Bone injury and implantation operation are often accompanied by microenvironment damage of bone tis-sue,which seriously affects the process of osseointegration of implants,especially for titanium(Ti)-based bioinert ma...Bone injury and implantation operation are often accompanied by microenvironment damage of bone tis-sue,which seriously affects the process of osseointegration of implants,especially for titanium(Ti)-based bioinert materials.Thus,repairing or improving the microenvironment of damaged bone tissue is of great significance for bone rescue,reconstruction,and regeneration,which is still a major medical challenge.Oxidative stress(OS)and oxygen(O_(2))deficiency are considered to be specific physiological signals of the bone-injury microenvironment.From the above background,a coating consisting of manganese dioxide(MnO_(2))nanoenzyme and strontium(Sr)ions was fabricated on the surface of the Ti implant via a one-step hydrothermal treatment.MnO_(2) nanoenzyme presented in the coating alleviated OS and O_(2) deficiency at the injury site by catalyzing the decomposition of abundant endogenous H_(2)O_(2) around the modified Ti implants into O_(2).In addition,Sr ions were released from the surface of the implant at a certain rate in a body-fluid environment,further promoting the adhesion,growth,and osteogenic differentiation of mesenchymal stem cells.More importantly,a Sprague Dawley rat femur model demonstrated that the modified Ti implant showed significant potential to accelerate bone tissue reconstruction in vivo.In sum-mary,the present system provides a new idea for the treatment of bone injury and the development of new orthopedic implants.展开更多
基金This study was financially supported by a UCL Impact Studentship in collaboration with Fitzpatrick Referrals Ltd.(award No.174064)European Commission via H2020 MSCA RISE BAMOS programme(project No.734156)+2 种基金Versus Arthritis(project No.21160)the Rosetree Trust(project No.A1184)and the Innovate UK via Newton Fund(No.102872).
文摘Osseointegrated transcutaneous implants could provide an alternative and improved means of attaching artificial limbs for amputees,however epithelial down growth,inflammation,and infections are common failure modalities associated with their use.To overcome these problems,a tight seal associated with the epidermal and dermal adhesion to the implant is crucial.This could be achieved with specific biomaterials(that mimic the surrounding tissue),or a tissue-specific design to enhance the proliferation and attachment of dermal fibroblasts and keratinocytes.The intraosseous transcutaneous amputation prosthesis is a new device with a pylon and a flange,which is specifically designed for optimising soft tissue attachment.Previously the flange has been fabricated using traditional machining techniques,however,the advent of additive layer manufacturing(ALM)has enabled 3-dimensional porous flanges with specific pore sizes to be used to optimise soft tissue integration and reduce failure of osseointegrated transcutaneous implants.The study aimed to investigate the effect of ALM-manufactured porous flanges on soft tissue ingrowth and attachment in an in vivo ovine model that replicates an osseointegrated percutaneous implant.At 12 and 24 weeks,epithelial downgrowth,dermal attachment and revascularisation into ALM-manufactured flanges with three different pore sizes were compared with machined controls where the pores were made using conventional drilling.The pore sizes of the ALM flanges were 700,1000 and 1250μm.We hypothesised that ALM porous flanges would reduce downgrowth,improve soft tissue integration and revascularisation compared with machined controls.The results supported our hypothesis with significantly greater soft tissue integration and revascularisation in ALM porous flanges compared with machined controls.
文摘Medical modeling and 3-dimensional(3D)virtual surgical planning represent a rapidly expanding,technological advancement especially useful in complex mandibular or maxillary defects in head and neck reconstruction.With utilization of 3D surgical planning,the reconstructive surgeon can initiate dental rehabilitation during the primary surgery with osseointegrated implants(OI),streamlining a typically lengthy process to full oral rehabilitation.Careful patient selection is important to optimize outcomes with immediate OI,and factors to consider during the evaluation process include pathology,prognosis,anticipated defect,dental status,donor site availability,and patient motivation and resources.Synthesizing this information and developing a reconstructive plan with a multidisciplinary team approach is critical to expedite dental rehabilitation for select patients.A review of relevant literature and our surgical planning algorithm for selecting candidates for immediate OI is provided,along with our experience using this decision algorithm in a uniquely complex clinical case.
文摘Aim:Ovine models for osseointegrated prosthetics research are well established,but do not consider neural control of advanced prostheses.The validity of interfacing technologies,such as the Osseointegrated Neural Interface(ONI),in their ability to provide communication between native nerves and advanced prosthetics is required,necessitating a stable,longitudinal large animal model for testing.The objective of this study is to provide a detailed anatomic description of the major nerves distal to the carpal and tarsal joints,informing the creation of a chronic ONI for prosthetic control in sheep.Methods:Six pelvic and six thoracic cadaveric limbs from mature female,non-lactating sheep were utilized.Radiographs were obtained to determine average bone length,medullary canal diameter,and cortical bone thickness.Microsurgical dissection was performed to discern topographical neuroanatomy and average circumferences of the major nerves of the pelvic and thoracic limbs.Histologic analysis was performed.A surgical approach for the creation of ONI was designed.Results:Average metacarpal and metatarsal length was 15.0 cm(±0.0)and 19.7 cm(±1.0),respectively.Average intramedullary canal diameter was 12.91 mm(±3.69)for forelimbs and 12.60 mm(±3.69)for hindlimbs.The thoracic limb nerves consisted of one dorsal and three ventral nerves,with an average circumference of 5.14 mm(±2.00)and 5.05 mm(±1.06),respectively.Pelvic limb nerves consisted of two dorsal and one ventral nerve with an average circumference of 6.27 mm(±1.79)and 5.40 mm(±0.53),respectively.Conclusions:These anatomic data inform the surgical approach and manufacture of a sensory ONI for chronic testing in awake,freely ambulating animals for future clinical translation.
基金supported by the National Natural Science Foundation of China(No.U21A2055),Natural Science Foundation of Tianjin of China(No.21JCQNJC01280)Tianjin Key R&D Program Beijing-Tianjin-Hebei Collaborative Innovation Project(No.22YFXTHZ00120).
文摘The poor surface conditions and osseointegration capacity of 3D printed Ti6Al4V implants(3DPT)significantly influence their performance as orthopedic and dental implants.In this work,we creatively introduce a one-step femtosecond laser treatment to improve the surface conditions and osteointegration.The surface characterization,mechanical properties,corrosion resistance,and biological responses were investigated.These results found that femtosecond laser eliminated defects like embedded powders and superficial cracks while forming the nano cones-like structures surface on 3DPT,leading to enhanced osseointegration,anti-corrosion,and anti-fatigue performance.Molecular dynamics simulations revealed the ablation removal mechanism and the formation of nano cone-like structures.These findings were further supported by the in vivo studies,showing that the FS-treated implants had superior bone-implant contact and osseointegration.Hence,the one-step femtosecond laser method is regarded as a promising surface modification method for improving the functional performance of Ti-based orthopedic implants.
基金the funding support from the Tianjin Medical University“Clinical Talent Training 123 Climbing Plan”the Youth Fund of Tianjin Medical University Second Hospital(No.2022ydey06)。
文摘Polyetheretherketone(PEEK)is a desirable candidate to replace conventional metal implants owing to its excellent mechanical properties.However,the intrinsic bioinertness of PEEK results in inferior or delayed osseointegration,which limits its further clinical application.To address these challenges,one leading strategy is to construct a biofunctionalized surface on PEEK that provides a coordinated osteoblastosteoclast interactions microenvironment.Herein,alendronate(ALN),a common bone absorption inhibitor,was loaded in biomedical inorganic/organic microspheres,consisting of bioactive inorganic nanohydroxyapatite core,and chitosan(CS)shell.Polydopamine(PDA)modification was employed to ensure the adherence of the microspheres to the PEEK surface.The delivery of ALN and Ca^(2+)from these microspheres simultaneously suppressed osteoclastogenesis and promoted osteogenesis,resulting in a coordinated cascade of osteoblast-osteoclast interactions crucial for the per-implant osseointegration.In vitro experiments demonstrated that the PEEK surface exhibited satisfactory biocompatibility and enhanced the proliferation and osteogenic differentiation of rat bone mesenchymal stem cells while inhibiting the osteoclast differentiation.Moreover,the in vivo rat femoral drilling model demonstrated superior osseointegration three months after implantation.By considering the bone remodeling processes,this study proposes a novel biofunctionalized PEEK surface that regulates the activities of both osteoblasts and osteoclasts to promote osseointegration.
基金the National Natural Science Foundation of China(Nos.31971246&52274387)the Fundamental Research Funds for the Central Universities(No.YG2023QNA21)the Shanghai Science and Technology Commission(No.20S31900100)for their financial and project support.
文摘The remodeling of macrophages mediated by biomaterials is an important step in osseointegration.The biointerfacial characteristics shaped by implants and the bioenergetic state derived from macrophages are considered the key to macrophage reprogramming.In this study,the integrated Ti/Zn composites with optimized morphology and bioactive phase were prepared by friction stir processing,which could meet the multi-biofunctional requirements in the application of narrow-diameter implants.The severe plastic deformation and the hindrance of Zn particles to grain growth promote grain refinement,resulting in enhanced mechanical properties.The cell interfacial adhesion mediated by the grain boundary collaborated the energy metabolism reprogramming induced by the released Zn ion,promoting jointly anti-inflammatory cascade in macrophages and favorable osteogenesis in bone marrow mesenchymal stem cells(BMSCs).This study provides a new simultaneous approach of morphology and composition modification for titanium implants,and reveals the important role of grain size and bioactive element in the reversion of macrophage fate as well.
基金supported by the National Natural Science Foundation of China(No.82202450).
文摘Large bone defects in load-bearing bone can result from tumor resection,osteomyelitis,trauma,and other factors.Although bone has the intrinsic potential to self-repair and regenerate,the repair of large bone defects which exceed a certain critical size remains a substantial clinical challenge.Traditionally,repair methods involve using autologous or allogeneic bone tissue to replace the lost bone tissue at defect sites,and autogenous bone grafting remains the“gold standard”treatment.However,the application of traditional bone grafts is limited by drawbacks such as the quantity of extractable bone,donor-site morbidities,and the risk of rejection.In recent years,the clinical demand for alternatives to traditional bone grafts has promoted the development of novel bone-grafting substitutes.In addition to osteoconductivity and osteoinductivity,optimal mechanical properties have recently been the focus of efforts to improve the treatment success of novel bone-grafting alternatives in load-bearing bone defects,but most biomaterial synthetic scaffolds cannot provide sufficient mechanical strength.A fundamental challenge is to find an appropriate balance between mechanical and tissue-regeneration requirements.In this review,the use of traditional bone grafts in load-bearing bone defects,as well as their advantages and disadvantages,is summarized and reviewed.Furthermore,we highlight recent development strategies for novel bone grafts appropriate for load-bearing bone defects based on substance,structural,and functional bionics to provide ideas and directions for future research.
文摘Mechanical loading constitutes a fundamental determinant in the process of bone remodeling.This modeling encompasses the incorporation of mechanical stimuli,the involvement of cellular and molecular constituents,as well as the utilization of sophisticated computational methodologies.Such an approach is imperative for forecasting bone behaviour across varying environmental conditions.In the present study,key findings from bone mechanobiology are reviewed,along with the possibility that Functionally Graded Materials(FGM)enhances osseointegration and lowers the stress-shielding effect during bone remodeling and compared to titanium,FGM improves periprosthetic bone remodeling.To summarise some of the most important findings from computational models of bone mechanobiology,explaining how modifications to the mechanical environment affect implant design,growth of bone,and bone response.The impact that changes related to the mechanical environment have on bone response is examined using computational models and methods such as surface microtopography to determine how an implant’s bone density has increased over time.This review focuses on the refinement of advanced simulation frameworks and their synergy with imaging technologies to strengthen model validation,ultimately resulting in better clinical outcomes in the context of bone health treatments.
基金supported by the National Natural Science Foundation of China(grant Nos.52301302,U22A20121,52175274,52111530042,and 5210010632)the China Postdoctoral Science Foundation(grant No.2023M732339)+1 种基金the Guangdong Basic and Applied Basic Research Foundation(Nos.2021A1515220086,2023A1515220095,and 2024A1515012042)the Beijing Natural Science Foundation(Grant No.L212014).
文摘Spinal fusion is a commonly used technique to treat acute and chronic spinal diseases by fusion of the adjacent vertebrae, aiming at achieving stability and eliminating the mobility of the objective segment. While bone autografts and allografts have been conventionally used for spinal fusion, limitations persist in achieving optimization of both good osteoinductive capacity and mechanical stability. In this study, additively manufactured Zn-Li scaffolds were developed and evaluated for their potential in spinal fusion. First, three scaffold structures (BCC, Diamond, and Gyroid) were designed and verified in vitro. Due to the smooth transition surfaces and uniform degradation behavior, the Gyroid Zn-Li scaffold demonstrated mechanical integrity during degradation and enhanced cellular proliferation compared to the other two scaffolds. Subsequently, Zn-Li scaffolds (Gyroid) were selected for posterolateral lumbar fusion (L4/L5) in rabbits. Following 12 weeks of implantation, the Zn-Li scaffolds demonstrated a moderate biodegradation rate and satisfactory biocompatibility. Compared to bone allografts, the Zn-Li scaffolds significantly improved osseointegration adjacent to the transverse processes, which led to enhanced segmental stability of the fused vertebrae post posterolateral lumbar fusion. Overall, the results show that the biodegradable Zn-Li scaffold holds substantial potential as the next-generation graft for spinal fusion.
基金supported bythe National Natural Science Foundation of China(Nos.U23A20523,82272504,and 82072456)the Department of Science and Technology of Jilin Province,China(Nos.20210101439JC,20210101321JC,20220204119YY,202201ZYTS131,202201ZYTS129,20230204114YY,YDZJ202201ZYTS505,and YDZJ202301ZYTS076)+4 种基金the Special Program for Science and Technology Personnel of Changchun(No.ZKICKJJ2023015)the Key Training Plan for Outstanding Youth of Jilin University(No.419070623036)the Research Fund of the First Hospital of Jilin University(No.2021-zl-01)the Graduate Innovation Fund of Jilin University(No.2024CX125)the Foun-dation of National Center for Translational Medicine(Shanghai)SHU Branch,China(No.SUITM-202405).
文摘The pore structure of porous scaffolds plays a crucial role in bone repair.The prevalent bone implant structure in clinical practice is the traditional cubic structure.However,the traditional cubic structure exhibits sharp edges and junctions that are not conducive to cell adhesion or growth.In this study,a double gyroid(DG)Ti6Al4V scaffold based on a triply periodic minimal surface(TPMS)structure was devised,and the osseointegration performance of DG structural scaffolds with varying porosities was investigated.Compression tests revealed that the elastic modulus and compressive strength of DG structural scaffolds were sufficient for orthopedic implants.In vitro cellular experiments demonstrated that the DG structure significantly enhanced cell proliferation,vascularization,and osteogenic differentiation compared to the cubic structure.The DG structure with 55%porosity exhibited the most favorable outcomes.In vivo experiments in rabbits further demonstrated that DG scaffolds could promote neovascularization and bone regeneration and maturation;those with 55%porosity performed best.Comparing the surface area,specific surface area per unit volume,and internal flow distribution characteristics of gyroid and DG structure scaffolds,the latter are more conducive to cell adhesion and growth within scaffolds.This study underscored the potential of DG scaffolds based on the TPMS structure in optimizing the pore structure design of titanium scaffolds,inducing angiogenesis,and advancing the clinical application of titanium scaffolds for repairing bone defects.
基金supported by the National Natural Science Foundation of China(No.82172398)Liaoning Revitalization Talents Program(No.XLYC2203102).
文摘In clinical settings,tantalum(Ta)is extensively implemented as a bone implant material.Ta is highly stable and biocompatible in vivo,being one of the metallic biomaterials having high affinity for bone tissue.However,since Ta is a refractory metal,its application as bone implant material is limited.Most recently,additive manufacturing technology has introduced a novel approach to producing Ta implants.The present study compared the microstructure,surface and mechanical characteristics,and in vitro and in vivo biological characteristics of selective laser melted Ta(SLM Ta),selective laser melted titanium alloy Ti6Al4V with Ta coating(SLM Ti6Al4V with Ta coating),and selective laser melted Ti6Al4V(SLM Ti6Al4V).Results indicate that SLM Ta possesses superior mechanical characteristics contrasted with SLM Ti6Al4V and SLM Ti6Al4V with Ta coating.Furthermore,SLM Ta has anti-inflammatory activity,excellent osseointegration performance,and osteogenic bioactivity.We fabricated an SLM porous Ta bone plate and employed it for internal fixation of ulnar and radius fractures,which has been known to promote fracture healing.Further,the SLM porous Ta bone plate could form an integrated bone plate structure with the bone tissue at the implant site.Afterward,the porous structure of the plate minimizes its elastic modulus and eliminates stress shielding,leaving no need for further surgical removal.In conclusion,the SLM porous Ta bone plate meets the performance requirements(stimulating bone regeneration,non-stress shelter,and no need for second surgery)of an ideal bone plate and may revolutionize the field of internal fixation bone plates for fractures.
基金Project(81571021) supported by the National Natural Science Foundation of ChinaProjects(2015WK3012,2018SK2017) supported by the Hunan Provincial Science and Technology Department Project,ChinaProject(20160301) supported by New Talent Project of the Third Xiangya Hospital of Central South University,China
文摘The effects of surface-modified porous titanium implants with different porosities and pore sizes on osseointegration were investigated in vivo.Three porous titanium implants(A30,A40 and A50 containing volume fractions of space-holder NaCl being 30%,40%and 50%,respectively)were manufactured by metal injection moulding(MIM).The surface-modified implants were implanted into muscles and femurs of hybrid male dogs.Interface osteogenic activity and histological bone ingrowth of porous titanium implants were evaluated at 28,56 and 84 d.The results showed that when additive space-holder amount of NaCl increased from 30%to 50%(volume fraction),the general porosity and mass fraction of macropores of porous titanium rose from 42.4%to 62.0%and from 8.3%to 69.3%,respectively.Histologic sections and fluorescent labeling showed that the A50 implant demonstrated a significantly higher osteogenic capacity at 28 d than other implants.Bone ingrowth into the A30 implant was lower than that into other implants at 84 d.Therefore,the pore structure of A50 implant was suitable for new bone tissue to grow into porous implant.
基金supported by grants from the National Natural Science Foundation of China(NSFC 81371173)the State Key Laboratory of Oral Diseases(SKLOD201704)+1 种基金the International Team for Implantology(Grant No.975_2014,Basel,Switzerland)the National Key R&D Program of China during the thirteenth Five-Year Plan(2016YFC1102700)
文摘Chronic kidney disease （CKD） is a worldwide public health problem that is growing in prevalence and is associated with severe complications. During the progression of the disease, a majority of CKD patients suffer oral complications. Dental implants are currently the most reliable and successful treatment for missing teeth. However, due to complications of CKD such as infections, bone lesions, bleeding risks, and altered drug metabolism, dental implant treatment for renal failure patients on dialysis is more challenging. In this review, we have summarized the characteristics of CKD and previous publications regarding dental treatments for renal failure patients. In addition, we discuss our recent research results and clinical experience in order to provide dental implant practitioners with a clinical guideline for dental implant treatment for renal failure patients undergoing hemodialysis.
基金Project supported by the National Natural Science Foundation of China (No. 81000462)the Zhejiang Provincial Natural Science Foundation (No. R2110374),China
文摘Objective:The purpose of this study was to investigate the effects of a zinc-substituted nano-hydroxyapatite(Zn-HA) coating,applied by an electrochemical process,on implant osseointegraton in a rabbit model.Methods:A Zn-HA coating or an HA coating was deposited using an electrochemical process.Surface morphology was examined using field-emission scanning electron microscopy.The crystal structure and chemical composition of the coatings were examined using an X-ray diffractometer(XRD) and Fourier transform infrared spectroscopy(FTIR).A total of 78 implants were inserted into femurs and tibias of rabbits.After two,four,and eight weeks,femurs and tibias were retrieved and prepared for histomorphometric evaluation and removal torque(RTQ) tests.Results:Rod-like HA crystals appeared on both implant surfaces.The dimensions of the Zn-HA crystals seemed to be smaller than those of HA.XRD patterns showed that the peaks of both coatings matched well with standard HA patterns.FTIR spectra showed that both coatings consisted of HA crystals.The Zn-HA coating significantly improved the bone area within all threads after four and eight weeks(P<0.05),the bone to implant contact(BIC) at four weeks(P<0.05),and RTQ values after four and eight weeks(P<0.05).Conclusions:The study showed that an electrochemically deposited Zn-HA coating has potential for improving bone integration with an implant surface.
基金support of the National Key R&D Program of China(No.2017YFB1104100)National Natural Science Foundation of China(No.81371129,81670973)+1 种基金the Science and Technology Commission of Shanghai(No.17410710500,16DZ0503800,17510710800)the Fund of Shanghai Municipal Commission of Health and Family Planning(No.201540369)
文摘Three-dimensional-printed(3 D-P)titanium implants display many advantages,such as design flexibility,higher efficiency,the capability to easily construct complex or customized structures,etc.,and is believed to potentially replace traditional implants.However,the biological performance of the 3 D-P titanium surface has not been investigated systematically.Herein,we analyzed the surface characteristics of 3 D-P Ti6 Al4 V implants and evaluated the biological responses of bone marrow derived mesenchymal stromal cells(BMSCs)to the 3 D-P surface in vitro.Moreover,after implantation into the rat femoral condyle for3 and 6 weeks,the osseointegration performance was evaluated.The results showed the 3 D-P Ti6 Al4 V implant presented distinct fluctuant macroscale rough surface and relatively better hydrophilicity which enhanced the adhesion,proliferation,osteogenic differentiation and angiogenetic factor expression of BMSCs.Moreover,the in vivo osseointegration performance was also better than that of the control group at the early stage.The present study suggested the 3 D-P titanium alloy is a promising candidate to be used as implant material.
基金financially supported by National Natural Science Foundation(Nos.51631009,51811530320 and 81572113)National Key Research and Development Program of China(Nos.2018YFC1106600 and 2016YFC1100600)+2 种基金Innovation Fund Project of Institute of Metal Research,Chinese Academy of Sciences(No.2017-ZD01)Key Projects for Foreign Cooperation of Bureau of International Cooperation Chinese Academy of Sciences(No.174321KYSB2018000)Shenzhen Science and Technology Research Funding(No.JCYJ20160608153641020)。
文摘Cu has been proved to possess various beneficial biological activities, while sandblasting and acid etching(SLA) is widely used to modify the commercial dental implant in order to improve osseointegration. Based on the above, a novel antimicrobial dental implant material, Ti-Cu alloy, was treated with SLA, to combine chemical design(Cu addition) and topographical modification(SLA). In this work, the effects of SLA treated Ti-Cu alloys(Ti-Cu/SLA) on osteogenesis, angiogenesis and antibacterial properties were evaluated from both in vitro and in vivo tests, and Ti/SLA and Ti-Cu(without SLA) were served as control groups. Benefiting by the combined effects of chemical design(Cu addition) and micro-submicron hybrid structures(SLA),Ti-Cu/SLA had significantly improved inhibitory effects on oral anaerobic bacteria(P. gingivalis and S.mutans) and could induce upregulation of osteogenic-related and angiogenic-related genes expression in vitro. More importantly, in vivo studies also demonstrated that Ti-Cu/SLA implants had wonderful biological performance. In the osseointegration model, Ti-Cu/SLA implant promoted osseointegration via increasing peri-implant bone formation and presenting good bone-binding, compared to Ti/SLA and Ti-Cu implants. Additionally, in the peri-implantitis model, Ti-Cu/SLA effectively resisted the bone resorption resulted from bacterial infection and meanwhile promoted osseointegration. All these results suggest that the novel multiple functional Ti-Cu/SLA implant with rapid osseointegration and bone resorption inhibition abilities has the potential application in the future dental implantation.
基金Supported by Sao Paulo Research Foundation,FAPESP,No.2008/06972-6The National Council for Scientific and Technological Development,CNPq Nos.579157/2008-3,302768/2009-2 and 473282/2007-0+1 种基金Pesq-Doc scholarship to Dr.Shibli from University of GuaruhosScholarship to Dr.Giro from University of Guarulhos
文摘AIM: To assess the failure and bone-to-implant contact rate of dental implants placed on osteoporotic subjects. METHODS: Extensive examination strategies were created to classify studies for this systematic review. MEDLINE(via Pub Med) and EMBASE database were examined for studies in English up to and including May 2014. The examination presented a combination of the MeS H words described as follow: "osteoporosis" or "osteopenia" or "estrogen deficiency" AND "implant" or "dental implant" or "osseointegration". Assessment of clinical and/or histological peri-implant conditions in osteoporosis subjects treated with titanium dental implants. The examination included a combination of the MeS H terms described as follow: "osteoporosis" or "osteopenia" or "estrogen deficiency" AND "implant" or "dental implant" or "osseointegration".RESULTS: Of 943 potentially eligible articles, 12 were included in the study. A total of 133 subjects with osteoporosis, 73 subjects diagnosed with osteopenia and 708 healthy subjects were assessed in this systematic review. In these subjects were installed 367, 205, 2981 dental implants in osteoporotic, osteopenic and healthy subjects, respectively. The failure rate of dental implant was 10.9% in osteoporotic subjects, 8.29% in osteopenic and 11.43% in healthy ones. Bone-to-implant contact obtained from retrieved implants ranged between 49.96% to 47.84%, for osteoporosis and non-osteoporotic subjects. CONCLUSION: Osteoporotic subjects presented higher rates of implant loss, however, there is a lower evidence to strengthen or refute the hypothesis that osteoporosis may have detrimental effects on bone healing. Consequently, final conclusions regarding the effect of osteoporosis in dental implant therapy cannot be made at this time. There are no randomized clinical trial accessible for evaluation and the retrospectivenature of the evaluated studies shall be taken in account when interpreting this study.
基金the State Key Project of Research and Development(Nos.2016YFC1100300 and 2017YFB0702603)the National Natural Science Foundation of China(Nos.51825302,21734002 and 51673032)。
文摘Titanium(Ti)and titanium alloys have become widely used as biomedical materials in orthopedics because of their good machinability,corrosion resistance,low elastic modulus and excellent biocompatibility.However,when Ti-based implants are used for bone repair and replacement,they are easy to cause bacteria adhesion and aggregation,which leads to postoperative infection.In addition,Ti and its alloys,as bio-inert materials,cannot induce desirable tissue responses such as osseointegration after implantation,which will eventually lead to implant loosening.Postoperative bacterial infection and lack of osseointegration directly lead to the failure of implantation surgery and are not conductive to the long-term service of titanium-based implants.Recently,researchers have made many attempts to focus on the surface modification of multifunctional Ti-based implants to endow them with both antibacterial activity and simultaneous osteoinductive property.In this review,we primarily highlighted the recent progresses in the surface design of Ti implants with both antimicrobial and osteoinductive properties for orthopedic applications.First,the challenges for treating implant-associated infections were briefly introduced such as the emergence of antibiotic resistance,the formation of biofilms,and the construction of cell-selective surfaces.Some of the essential fundamentals were concisely introduced to address these emerging challenges.Next,we intended to elaborate the potential strategies of multifunctional surface design to endow good osseointegration for antibacterial Ti implants and highlighted the recent advances of the implants.We hope that this review will provide theoretical basis and technical support for the development of new Ti implant with antibacterial and osteogenic functions.
文摘Additive manufacturing of porous, open-cellular metal or alloy implants, fabricated by laser or electron beam melting of a powder bed, is briefly reviewed in relation to optimizing biomechanical compatibility by assuring elastic(Young's) modulus matching of proximate bone, along with corresponding pore sizes assuring osseointegration and vasculature development and migration. In addition, associated, requisite compressive and fatigue strengths for such implants are described. Strategies for optimizing osteoblast(bone cell) development and osteoinduction as well as vascularization of tissue in 3 D scaffolds and tissue engineering constructs for bone repair are reviewed in relation to the biology of osteogenesis and neovascularization in bone, and the role of associated growth factors, bone morphogenic proteins, signaling molecules and the like. Prospects for infusing hydrogel/collagen matrices containing these cellular and protein components or surgically extracted intramedullary(bone marrow) concentrate/aspirate containing these biological and cell components into porous implants are discussed, as strategies for creating living implants, which over the long term would act as metal or alloy scaffolds.
基金financially supported by the National Natu-ral Science Foundation of China (Nos.32171327,21734002,and 51825302)the Natural Science Foundation of Chongqing (No.cstc2021jcyj-cxttX0002).
文摘Bone injury and implantation operation are often accompanied by microenvironment damage of bone tis-sue,which seriously affects the process of osseointegration of implants,especially for titanium(Ti)-based bioinert materials.Thus,repairing or improving the microenvironment of damaged bone tissue is of great significance for bone rescue,reconstruction,and regeneration,which is still a major medical challenge.Oxidative stress(OS)and oxygen(O_(2))deficiency are considered to be specific physiological signals of the bone-injury microenvironment.From the above background,a coating consisting of manganese dioxide(MnO_(2))nanoenzyme and strontium(Sr)ions was fabricated on the surface of the Ti implant via a one-step hydrothermal treatment.MnO_(2) nanoenzyme presented in the coating alleviated OS and O_(2) deficiency at the injury site by catalyzing the decomposition of abundant endogenous H_(2)O_(2) around the modified Ti implants into O_(2).In addition,Sr ions were released from the surface of the implant at a certain rate in a body-fluid environment,further promoting the adhesion,growth,and osteogenic differentiation of mesenchymal stem cells.More importantly,a Sprague Dawley rat femur model demonstrated that the modified Ti implant showed significant potential to accelerate bone tissue reconstruction in vivo.In sum-mary,the present system provides a new idea for the treatment of bone injury and the development of new orthopedic implants.
