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BACKGROUND: The head plays an important role in the postural control. Chewing co-activates jaw and neck muscles leading to coordinated jaw and head-neck movements. Therefore, to examine effect of masticatory movements on head and trunk sways, and sitting and foot pressure distributions during mastication is helpful in the attempt to understand the interrelationship between stomatognathic function and posture control system in the sitting position. OBJECTIVES: The purpose of this study was to test the hypothesis in healthy subjects that masticatory movements affect head and trunk sways and sitting and foot pressure distributions during sitting position. METHODS: A total of 30 healthy male subjects with an average age of 25.3 years (range, 22-32 years) were evaluated. The CONFORMat™ and MatScan™ system were used to analyse changes in sitting pressure distribution center of sitting pressure (COSP) and changes in foot pressure distribution center of foot pressure (COFP), respectively, and the three-dimensional motion analysis system was used to analyse changes in head and trunk postures while subjects remained sitting position with rest position, centric occlusion and chewing. The total trajectory length of COSP/COFP, COSP/COFP area, and head and trunk sway values were compared between the three conditions to evaluate whether masticatory movement affected the stability of head and trunk sways and sitting and foot pressure distributions. RESULTS: Total trajectory length of COSP and COSP area during chewing were significantly shorter and smaller respectively than it was in rest position and centric occlusion (p ⟨ .016). Head sway value during chewing was significantly larger than it was in rest position and centric occlusion (p ⟨ .016). CONCLUSION: Masticatory movements affect sitting pressure distribution and head movements during sitting position.
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In this study, we examined the immunolocalization of podoplanin/E11, CD44, actin filaments, and phosphorylated ezrin in the osteoblasts on the verge of differentiating into osteocytes in murine femora and tibiae. When observing under stimulated emission depletion microscopy, unlike podoplanin-negative osteoblasts, podoplanin-positive osteoblasts showed a rearranged assembly of actin filaments along the cell membranes which resembled that of embedded osteocytes. In the metaphysis, i.e., the bone remodeling site, CD44-bearing osteoclasts were either proximal to or in contact with podoplanin-positive osteoblasts, but the podoplanin-positive osteoblasts also localized CD44 on their own cell surface. These podoplanin-positive osteoblasts, which either possessed CD44 on their cell surface or were close to CD44-bearing osteoclasts, showed phosphorylated ezrin-positivity on the cell membranes. Therefore, the CD44/podoplanin interaction on the cell surface may be involved in the osteoblastic differentiation into osteocytes in the metaphyses, via the mediation of podoplanin-driven ezrin phosphorylation and the subsequent reorganized assembly of actin filaments. Consistently, the protein expression of phosphorylated ezrin was increased after CD44 administration in calvarial culture. Conversely, in modeling sites such as the cortical bones, podoplanin-positive osteoblasts were uniformly localized at certain intervals even without contact with CD44-positive bone marrow cells; furthermore, they also exhibited phosphorylated ezrin immunoreactivity along their cell membranes. Taken together, it seems likely that the CD44/podoplanin interaction is involved in osteoblastic differentiation into osteocytes in the bone remodeling area but not in modeling sites.
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Osso e Ossos/citologia , Glicoproteínas de Membrana/análise , Osteoblastos/citologia , Osteócitos/citologia , Animais , Remodelação Óssea , Osso e Ossos/química , Diferenciação Celular , Imuno-Histoquímica , Masculino , Camundongos , Camundongos Endogâmicos ICR , Osteoblastos/química , Osteócitos/químicaRESUMO
PURPOSE: To evaluate the inhibitory effect of a surface pre-reacted glass-ionomer (S-PRG) filler-containing tooth-coating material on enamel demineralization. The outer surface of the S-PRG filler is in a state in which ions are readily released. METHODS: Human enamel blocks were incubated in lactic acid solution (pH 4.0) with and without a disk (n=6) made of the cured tooth-coating material. Test solutions were changed every 24 hours and incubation was continued for 4 days. The pH and amount of fluoride released were measured with an electrode and ion meter, respectively. The concentrations of ions (aluminum, boron, calcium, phosphorus, silicon, sodium, and strontium) were measured by inductively coupled plasma atomic emission spectroscopy. The surface of the enamel block was observed with a scanning electron microscope. RESULTS: Enamel demineralization was not observed in an enamel block incubated with a disk of the tooth-coating material. Ions released from S-PRG filler had an acid buffering action in the low pH lactic acid solution. However, in the enamel block-only solution showing high levels of calcium ion release, the degree of demineralization was correlated with morphological changes of the enamel surface. CLINICAL SIGNIFICANCE: Due to the buffering effects of the pre-reacted glass-ionomer surface by ion release, the S-PRG filler-containing tooth-coating material inhibited enamel demineralization by neutralizing the acidic environment at an early time point.
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Esmalte Dentário , Desmineralização do Dente , Materiais Dentários , Fluoretos , Cimentos de Ionômeros de Vidro , HumanosRESUMO
Upon liver injury, excessive deposition of collagen from activated hepatic stellate cells (HSCs) is a leading cause of liver fibrosis. An understanding of the mechanism by which collagen biosynthesis is regulated in HSCs will provide important clues for practical anti-fibrotic therapy. Endoplasmic reticulum oxidase 1α (ERO1α) functions as an oxidative enzyme of protein disulfide isomerase, which forms intramolecular disulfide bonds of membrane and secreted proteins. However, the role of ERO1α in HSCs remains unclear. Here, we show that ERO1α is expressed and mainly localized in the endoplasmic reticulum in human HSCs. When HSCs were transfected with ERO1α siRNA or an ERO1α shRNA-expressing plasmid, expression of ERO1α was completely silenced. Silencing of ERO1α expression in HSCs markedly suppressed their proliferation but did not induce apoptosis, which was accompanied by impaired secretion of collagen type 1. Silencing of ERO1α expression induced impaired disulfide bond formation and inhibited autophagy via activation of the Akt/mammalian target of rapamycin signaling pathway, resulting in intracellular accumulation of collagen type 1 in HSCs. Furthermore, silencing of ERO1α expression also promoted proteasome-dependent degradation of membrane type 1-matrix metalloproteinase (MT1-MMP), which stimulates cell proliferation through cleavage of secreted collagens. The inhibition of HSC proliferation was reversed by treatment with MT1-MMP-cleaved collagen type 1. The results suggest that ERO1α plays a crucial role in HSC proliferation via posttranslational modification of collagen and MT1-MMP and, therefore, may be a suitable therapeutic target for managing liver fibrosis.
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Colágeno Tipo I/metabolismo , Células Estreladas do Fígado/citologia , Células Estreladas do Fígado/metabolismo , Metaloproteinase 14 da Matriz/metabolismo , Glicoproteínas de Membrana/metabolismo , Oxirredutases/metabolismo , Autofagia , Linhagem Celular , Proliferação de Células , Ativação Enzimática , Inativação Gênica , Humanos , Integrinas/metabolismo , Glicoproteínas de Membrana/deficiência , Glicoproteínas de Membrana/genética , Oxirredutases/deficiência , Oxirredutases/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de SinaisRESUMO
Early and immediate loading of dental implants has become a routine procedure in dental practices throughout the world, but the histological feature of peri-implant bone has not been fully understood. Therefore, we aimed to elucidate the histological response of peri-implant bone bearing the early occlusal loading using rat models. Four-week-old male Wistar rats were subjected to extraction of their maxillary left first molars and had titanium implants inserted immediately into the post-extraction sockets. In experimental groups at 1 week after placement, implants were loaded for 1 or 2 weeks by adding adhesive resin on the top of the screws. In control groups, no adhesive resin was added to the implants. After 1 or 2 weeks with loading, rats were fixed with an aldehyde solution for histochemical assessment. Newly-formed bone adhered broadly to the implant surface in both the control and experimental groups. The experimental group loaded for 2 weeks showed thicker trabeculae between the implant threads compared to those in the control group. Osteopontin- and osteocalcin-positive cement lines, which are histological hallmarks of bone remodeling, were narrow and smooth in the experimental groups, while featuring a complex meshwork with thick scalloped lines in the control groups. The index of sclerostin-positive osteocytes located close to implants loaded for 2 weeks was significantly lower than in controls, suggesting that osteoblast activity was preserved. Summarizing, our experimental model suggested that early implant loading increases trabecular thickness in the peri-implant bone tissue in a process that involves the regulation of bone remodeling.
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Implantes Dentários , Carga Imediata em Implante Dentário , Alvéolo Dental , Animais , Masculino , Ratos , Ratos WistarRESUMO
Human adenovirus is a promising tool for cancer therapy as an oncolytic virus. To predict which region of the oncolytic adenovirus E4 gene could be deleted, we investigated the relationship between the E4 proteins and NF-κB. Here, we report that TLR2-dependent NF-κB activation in Ad5-infected cells was significantly inhibited 24 h post-infection. Among the six E4 proteins, E4 orf4 and E4 orf6/7 exhibited notable suppressive effects on NF-κB activation. However, only E4 orf4 was co-immunoprecipitated with the RelA protein, also known as p65. It appears likely that E4 orf6/7 represses NF-κB activation via E2F-dependent pathways. Our results suggest that both E4 orf4 and E4 orf6/7 are novel inhibitors of NF-κB activation. The inhibition of endogenous NF-κB activation by E4 proteins during the late phase of infection also appears to elucidate the previously reported suppression of E1A expression in the late phase of infection. These redundant suppressive effects of E4 orf4 and E4 orf6/7 on NF-κB suggest that these proteins may play a major role in the anticancer properties of oncolytic adenovirus.
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Dental implant therapy is a reliable treatment for replacing missing teeth. However, as dental implants become more widely used, peri-implantitis increasingly has become a severe complication, making successful treatment more difficult. As a result, the development of effective drug delivery systems (DDSs) and treatments for peri-implantitis are urgently needed. Carbon nanohorns (CNHs) are carbon nanomaterials that have shown promise for use in DDSs and have photothermal effects. The present study exploited the unique properties of CNHs to develop a phototherapy employing a near-infrared (NIR) photoresponsive composite of minocycline, hyaluronan, and CNH (MC/HA/CNH) for peri-implantitis treatments. MC/HA/CNH demonstrated antibacterial effects that were potentiated by NIR-light irradiation, a property that was mediated by photothermal-mediated drug release from HA/CNH. These antibacterial effects persisted even following 48 h of dialysis, a promising indication for the clinical use of this material. We propose that the treatment of peri-implantitis using NIR and MC/HA/CNH, in combination with surgical procedures, might be employed to target relatively deep affected areas in a timely and efficacious manner. We envision that this innovative approach will pave the way for future developments in implant therapy.
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Antibacterianos , Carbono , Ácido Hialurônico , Raios Infravermelhos , Minociclina , Peri-Implantite , Ácido Hialurônico/química , Ácido Hialurônico/farmacologia , Peri-Implantite/tratamento farmacológico , Peri-Implantite/terapia , Minociclina/química , Minociclina/farmacologia , Antibacterianos/química , Antibacterianos/farmacologia , Carbono/química , Animais , Humanos , Camundongos , Nanoestruturas/química , Nanoestruturas/uso terapêutico , Sistemas de Liberação de Medicamentos , Liberação Controlada de FármacosRESUMO
Multi-walled carbon nanotubes (MWCNTs) were functionalized with fibroblast growth factor (FGF) and the advantages of their use as scaffolds for bone augmentation were evaluated in vitro and in vivo. The activity of FGF was assessed by measuring the effect on the proliferation of rat bone marrow stromal cells (RBMSCs). The presence of FGF enhanced the proliferation of RBMSCs and the FGF covalently conjugated to the nanotubes (FGF-CNT) showed the same effect as FGF alone. In addition, FGF-CNT coated sponges were implanted between the parietal bone and the periosteum of rats and the formation of new bone was investigated. At day 14 after implantation, a larger amount of newly formed bone was clearly observed in most pores of FGF-CNT coated sponges. These findings indicated that MWCNTs accelerated new bone formation in response to FGF, as well as the integration of particles into new bone during its formation. Scaffolds coated with FGF-CNT could be considered as promising novel substituting materials for bone regeneration in future tissue engineering applications.
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Proliferação de Células/efeitos dos fármacos , Fator 2 de Crescimento de Fibroblastos/farmacologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/fisiologia , Nanotubos de Carbono/química , Osteogênese/efeitos dos fármacos , Animais , Regeneração Óssea/efeitos dos fármacos , Regeneração Óssea/fisiologia , Células Cultivadas , Fator 2 de Crescimento de Fibroblastos/química , Masculino , Células-Tronco Mesenquimais/citologia , Ratos , Ratos Wistar , Engenharia TecidualRESUMO
OBJECTIVES: We investigated the behavior of macrophages in the defined microtopography of materials. METHODS: Patterned cyclo-olefin polymer films were implanted into the femurs of seven-week-old rats. After 1 and 4 weeks, the rats were fixed with glutaraldehyde and OsO4, and their bones were observed with transmission electron microscopy (TEM). RESULTS: TEM and segmentation revealed an alternating structure in which multiple protrusions of adjacent macrophage-like cells overlapped. They were approximately 2 µm long and almost uniform in width, and were induced by the limited topography. CONCLUSION: New structures appeared between the macrophage-like cells as a result of microtopography.
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Macrófagos , Ratos , Animais , Microscopia Eletrônica de Transmissão , GlutaralRESUMO
PURPOSE: To verify the effect of sitting posture with and without sole-ground contact on chewing stability and masticatory performance. METHODS: Thirty healthy subjects were evaluated. The Conformat was used to analyze the center of sitting pressure (COSP), and the three-dimensional motion analysis system was used to analyze changes in head and trunk postures while subjects remained in a sitting position with and without sole-ground contact. The parameters of masticatory performance and movement were calculated as follows. For evaluating masticatory performance, the amount of glucose extraction (AGE) during chewing of a gummy jelly was measured. For evaluating masticatory movements, the movement of the mandibular incisal point was recorded using the Motion Visi-Trainer V1, and parameters of the stabilities of movement path and rhythm were calculated. RESULTS: Head and trunk sway values and the displacement of COSP were significantly smaller with sole-ground contact than those without sole-ground contact. The masticatory movement path with sole-ground contact showed less variation in the opening distance and more stable movement path compared to those without sole-ground contact. The AGE was significantly greater with sole-ground contact than that without sole-ground contact. CONCLUSION: Sitting posture with and without sole-ground contact affects chewing stability and masticatory performance.
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This study developed a novel antibacterial conjugate based on carbon nanohorns for peri-implantisis, an inflammatory disease around dental implants, which may result in failing implants by bone loss around them. The conjugate demonstrates much better photodurability than commonly used indocyanine green and a significant antibacterial effect under NIR illumination.
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Peri-Implantite , Humanos , Peri-Implantite/tratamento farmacológico , Antibacterianos/farmacologia , Carbono , Verde de Indocianina/farmacologia , IluminaçãoRESUMO
BACKGROUND: Implant-supported removable partial dentures (ISRPDs) provide effective prosthodontic treatment for partially edentulous patients. ISRPDs offer greater patient satisfaction and better oral function compared with removable partial dentures (RPDs) by enhancing denture stability and support. However, few clinical studies have focused on RPD design in patients with mandibular Kennedy Class II edentulism. The aim of this case reports was to investigate the oral function, oral health-related quality of life, and satisfaction of four patients with unilateral distal-extension mandibular RPDs with the same design which were replaced with ISRPDs. In addition, we investigated how each patient's evaluation varied with the change from RPD to ISRPD. CASE PRESENTATION: Four patients had unilateral distal-extension mandibular edentulism and were missing the first and second molars and the first and second premolars. They received one implant (4.0 mm in diameter, 8.0 mm in length; IAT EXA PLUS Bone level; Nippon Piston Ring Co. Ltd, Saitama, Japan) at the position equivalent to the first molar in the edentulous residual ridge perpendicular to the occlusal plane. Implant position was determined by surgical guide plate. RPDs were fabricated after the residual mucosal membrane had healed. The basic design of the RPD was as follows: a cobalt-chromium alloy cast metal framework denture with a lingual bar as the major connector, a double Akers clasp on the molars and an auxiliary retainer on the premolar as indirect retainers, and a wrought wire clasp and a cast cingulum rest (combination clasp) as direct retainers. Masticatory performance, occlusal force, oral health-related quality of life, and satisfaction were estimated at baseline, and at time points after insertion of the RPD and after insertion of the adapted ISRPD. Each evaluation item showed a tendency for improvement on insertion of the new RPD. Masticatory performance and satisfaction tended to be better after insertion of the ISRPD than after insertion of the RPD. CONCLUSION: Our findings suggest that ISRPDs provided better patient satisfaction and masticatory performance than RPDs in patients with mandibular Kennedy Class II edentulism. Trial registration UMIN Clinical Trials Registry and Japan Registry of Clinical Trials, UMIN000025283 and jRCTs012180003. Registered 19 February 2016 and 17 December 2018, https://www.umin.ac.jp/ and https://jrct.niph.go.jp/.
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Implantes Dentários , Prótese Parcial Removível , Boca Edêntula , Humanos , Qualidade de Vida , Pesquisa , Grampos DentáriosRESUMO
Residual ridge resorption (RRR) is a chronic and progressive bone resorption following tooth loss. It causes deterioration of the oral environments and leads to the pathogenesis of various systemic diseases. However, the molecular mechanisms and risk factors for RRR progression are still unclear and controversial. In this study, we developed a tooth extraction model using mice for analyzing long-term morphological and gene expression changes in the alveolar bone. We further applied ovariectomy to this model to elucidate the effects of osteoporosis on RRR progression. As a result, the alveolar bone loss was biphasic and consisted of rapid loss in the early stages and subsequently slow and sustained bone loss over a long period. Histological analysis indicated that ovariectomy prolonged the activation of osteoclasts in the alveolar bone. Furthermore, the expressions of Tnfsf11 and Sema4d kept increasing for a long time in OVX mice. Administration of neutralization antibodies for receptor activator of NF-κB ligand (RANKL) effectively suppressed RRR. Similarly, inhibition of Semaphorin 4D (Sema4D) also improved alveolar bone loss. This study demonstrated that reduced ovarian function may be a risk factor for RRR and that RANKL and Sema4D suppression are potential treatments.
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Perda do Osso Alveolar , Conservadores da Densidade Óssea , Reabsorção Óssea , Semaforinas , Perda do Osso Alveolar/patologia , Animais , Antígenos CD/metabolismo , Conservadores da Densidade Óssea/farmacologia , Reabsorção Óssea/metabolismo , Feminino , Humanos , Ligantes , Camundongos , Camundongos Endogâmicos C57BL , NF-kappa B/metabolismo , Osteoclastos/metabolismo , Osteogênese , Ovariectomia/efeitos adversos , Ligante RANK/metabolismo , Semaforinas/genética , Semaforinas/metabolismoRESUMO
BACKGROUND: There have been several reports about the prognosis of teeth adjacent to edentulous spaces for implant-supported fixed prostheses (ISFPs) and removable partial dentures (RPDs). However, there are few reports about the prognosis of the other remaining teeth comparing ISFPs with RPDs. PURPOSE: The aim of this study was to evaluate and compare the prognosis of the remaining teeth for ISFPs and RPDs in terms of survival and complication-free rates. METHODS: Subjects were partially edentulous patients with ISFPs or RPDs inserted in 2003-2016. Teeth adjacent to edentulous spaces (A-teeth), teeth not adjacent to edentulous spaces (R-teeth), and teeth opposing edentulous spaces (O-teeth) were investigated. The endpoints were tooth extraction and complications. A multivariate cox regression model was used to estimate the risk factors for survival of the investigated teeth. RESULTS: A total of 233 (ISFP: 89, RPD: 144) patients were included in the statistical analyses. An IFSP prosthesis, when compared to an RPD prosthesis did not significantly decrease the tooth loss rate for A-teeth (hazard ratio [HR]: 0.76; 95% confidence interval [CI]: 0.30-1.92), for R-teeth (HR: 0.54; 95% CI: 0.28-1.05), or for O-teeth (HR: 0.45; 95% CI: 0.10-2.09). CONCLUSIONS: In partially edentulous spaces, the difference between ISFPs and RPDs does not affect the prognosis of teeth adjacent to edentulous spaces, teeth not adjacent to edentulous spaces, and teeth opposing edentulous spaces. Namely, our findings suggest that it depends largely on the tooth type, jaw, endodontic therapy performed, not on the type of prostheses.
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Implantes Dentários , Prótese Parcial Removível , Arcada Parcialmente Edêntula , Prótese Dentária Fixada por Implante/efeitos adversos , Humanos , Prognóstico , Estudos RetrospectivosRESUMO
This study examined the controlled release of cetylpyridinium chloride (CPC) from a tissue conditioner (TC) containing CPC-montmorillonite (CPC-Mont), the associated antimicrobial activity, and oral mucosa irritation. The CPC release test was performed daily for 28 days in three test solutions: distilled water, 0.2 M NaCl, and 0.2 M HCl. The antimicrobial activities for 7, 14, 21, and 28 days against Candida albicans, Staphylococcus aureus, and Streptococcus mutans were assessed according to the JIS Z 2801/ISO 22196 standard. An oral mucosa irritation test was conducted using cheek pouches in five male hamsters according to the ISO 10993-10:2010 standard. The amount of CPC released each day and the cumulative amount released over 28 days (6.12 mg) were less than the daily safe maximum of sore throat medicines (8 mg). Additionally, TC with CPC-Mont could sustain antimicrobial activity against adherent bacteria for 14 days and has no oral mucosa irritation potential.
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Anti-Infecciosos Locais , Cetilpiridínio , Anti-Infecciosos Locais/toxicidade , Bentonita/toxicidade , Cetilpiridínio/toxicidade , Preparações de Ação Retardada , Humanos , Masculino , Mucosa BucalRESUMO
OBJECTIVE: To evaluate the effect of body posture on occlusal contact. METHODS: A total of 30 healthy subjects were evaluated. T-Scan™ III was used to analyze the center of occlusal force (COF) and occlusal force distribution while subjects remained supine (SP), upright sitting with the head fixed (UP-HFI), upright sitting with the head free (UP-HFR), and natural standing (NS). RESULTS: The total trajectory length of COF was significantly longer in NS than in SP, UP-HFI, and UP-HFR. The COF area was significantly larger in UP-HFR than in SP and UP-HFI and also significantly larger in NS than in SP, UP-HFI, and UP-HFR. The anteroposterior occlusal force distribution (AOD) in NS shifted significantly forward, compared to SP, UP-HFI, and UP-HFR. AOD in UP-HFI and UP-HFR shifted significantly forward, compared to the SP position. CONCLUSION: Changes in body posture affect the stability and anteroposterior balance of occlusal contacts.
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Carbon nanotubes (CNTs) are potentially important biomaterials because of their chemical, physical, and biological properties. Our research indicates that CNTs exhibit high compatibility with bone tissue. The guided bone regeneration (GBR) technique is commonly applied to reconstruct alveolar bone and treat peri-implant bone defects. In GBR, bone defects are covered with a barrier membrane to prevent the entry of nonosteogenic cells such as epithelial cells and fibroblasts. The barrier membrane also maintains a space for new bone formation. However, the mechanical and biological properties of materials previously used in clinical practice sometimes delayed bone regeneration. In this study, we developed a CNT-based membrane for GBR exhibiting high strength to provide a space for bone formation and provide cellular shielding to induce osteogenesis. The CNT membrane was made via the dispersion of single-walled CNTs (SWCNTs) in hyaluronic acid solution followed by filtration. The CNT membrane assumed a nanostructure surface due to the bundled SWCNTs and exhibited high strength and hydrophilicity after oxidation. In addition, the membrane promoted the proliferation of osteoblasts but not nonosteogenic cells. CNT membranes were used to cover experimental bone defects made in rat calvaria. At 8 weeks after surgery, more extensive bone formation was observed in membrane-covered defects compared with bone defects not covered with membrane. Almost no diffusion of CNTs was observed around the membrane. These results indicate that the CNT membrane has adequate strength, stability, and surface characteristics for osteoblasts, and its shielding properties promote bone formation. Demonstration of the safety and osteogenic potential of the CNT membranes through further animal studies should facilitate their clinical application in GBR.
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Nanotubos de Carbono , Osteogênese , Animais , Regeneração Óssea , Membranas Artificiais , Osteoblastos , RatosRESUMO
A recent study showed that carbon nanohorns (CNHs) have biocompatibility and possible medical uses such as in drug delivery systems. It was reported that some kinds of carbon nanomaterials such as carbon nanotubes were useful for bone formation. However, the effect of CNHs on bone tissue has not been clarified. The purpose of this study was to evaluate the effect of CNHs on bone regeneration and their possible application for guided bone regeneration (GBR). CNHs dispersed in ethanol were fixed on a porous polytetrafluoroethylene membrane by vacuum filtration. Cranial defects were created in rats and covered by a membrane with/without CNHs. At two weeks, bone formation under the membrane with CNHs had progressed more than under that without CNHs and numerous macrophages were observed attached to CNHs. At eight weeks, there was no significant difference in the amount of newly formed bone between the groups and the appearance of macrophages was decreased compared with that at two weeks. Newly formed bone attached to some CNHs directly. These results suggest that macrophages induced by CNHs are related to bone regeneration. In conclusion, the present study indicates that CNHs are compatible with bone tissue and effective as a material for GBR.
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Regeneração Óssea/efeitos dos fármacos , Regeneração Tecidual Guiada/métodos , Nanotubos de Carbono/química , Crânio/fisiologia , Animais , Doenças Ósseas/tratamento farmacológico , Doenças Ósseas/cirurgia , Modelos Animais de Doenças , Histocitoquímica , Macrófagos , Masculino , Teste de Materiais , Microscopia Eletrônica de Transmissão , Ratos , Ratos Wistar , Crânio/efeitos dos fármacos , Crânio/cirurgiaRESUMO
The purpose of this study was to quantitatively evaluate the effects of experimental leg length discrepancies on body posture and dental occlusion. Thirty asymptomatic subjects (15 males and 15 females, ages 19-33, mean age 25.6 years) were included in this study and randomly assigned to one of two groups based on a table of random numbers. The only difference between group A and group B was the sequence of testing. Experimental leg length discrepancies were provided by using ten types of insoles with heights ranging from one to ten mm at one mm intervals, placed under both feet. The MatScan (Nitta Corp., Osaka, Japan) system was used to measure changes in body posture (center of foot pressure: COP) while subjects maintained the following three postural positions: 1. natural standing posture (control); 2. control with a heel lift under the right foot; or 3. control with a heel lift under the left foot. The T-Scan II system (Nitta Corp., Osaka, Japan) was used to analyze the results of changes in dental occlusion (center of occlusal force: COF) in the above-mentioned three postural positions. When subjects used a heel lift of six mm or more under the right foot, lateral weight distribution (LWD) shifted to the right side compared to the control (p<0.05). When a heel lift of four mm or more was used under the left foot, LWD shifted to the left side compared to the control (p<0.05). When subjects used a heel lift of eight mm or more under the right foot, occlusal force shifted to the right side compared to the control (p<0.05). When subjects used a heel lift of seven mm or more under the left foot, occlusal force shifted to the left side compared to the control (p<0.05). Based on these findings, it was concluded that leg length discrepancy affected body posture and dental occlusion.
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Oclusão Dentária , Desigualdade de Membros Inferiores/fisiopatologia , Postura , Adulto , Fenômenos Biomecânicos , Pesos e Medidas Corporais , Feminino , Humanos , Masculino , Processamento de Sinais Assistido por Computador , Estatísticas não Paramétricas , Adulto JovemRESUMO
Direct contact between bone and implant materials is required for dental implants. Titanium is used for the implant material owing to its mechanical and biological properties. The anodisation as the surface treatment was employed to enhance osteogenesis around titanium. Moreover, carbon nanohorn (CNH), a type of nanometer-sized carbon material, was reported to promote the bone formation. Thus, it is expected that if the surface of anodised Ti (AnTi) is modified with CNHs, Ti-bone contact would be enhanced. In this study, the Ti surface was modified with CNHs by electrophoresis and obtained anodised titanium coated with CNHs (CNH/AnTi). In vitro, CNH/AnTi attracted osteoblastic cells more than AnTi, thereby the proliferation of osteoblastic cell was enhanced by CNH/AnTi more than by AnTi. In vivo, at 7 and 28 days after implantation of CNH/AnTi or AnTi into the rat femur, more aggressive bone formation was observed on the surface of CNH/AnTi than on AnTi. More importantly, the area where newly formed bone tissue directly attached to CNH/AnTi was significantly larger than that for AnTi, suggesting that "contact osteogenesis" was accelerated on CNH/AnTi during the early post-implantation period. CNH/AnTi would be advantageous especially for the early stages of bone regeneration after surgery.