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1.
Basic Clin Androl ; 31(1): 12, 2021 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-34011267

RESUMO

BACKGROUND: Sperm growth and maturation are correlated with the expression levels of Leucine-rich repeat and WD repeat-containing protein 1 (LRWD1), a widely expressed protein in the human testicles. The decrease in LRWD1 cellular level was linked to the reduction in cell growth and mitosis and the rise in cell microtubule atrophy rates. Since DNA methylation has a major regulatory role in gene expression, this study aimed at exploring the effect of the modulation of DNA methylation on LRWD1 expression levels. RESULTS: The results revealed the presence of a CpG island up of 298 bps (- 253 ~ + 45) upon LRWD1 promoter in NT2/D1 cells. The hypermethylation of the LRWD1 promoter was linked to a reduction in the transcription activity in NT2/D1 cells, as indicated by luciferase reporter assay. The methylation activator, floxuridine, confirmed the decrease in the LRWD1 promoter transcriptional activity. On the other hand, 5-Aza-2'-deoxycytidine (5-Aza-dc, methylation inhibitor), significantly augmented LRWD1 promoter activity and the expression levels of mRNA and proteins. Furthermore, DNA methylation status of LRWD1 promoter in human sperm genomic DNA samples was analyzed. The results indicated that methylation of LRWD1 promoter was correlated to sperm activity. CONCLUSIONS: Thus, the regulation of LRWD1 expression is correlated with the methylation status of LRWD1 promoter, which played a significant role in the modulation of spermatogenesis, sperm motility, and vitality. Based on these results, the methylation status of LRWD1 promoter may serve as a novel molecular diagnostic marker or a therapeutic target in males' infertility.


RéSUMé: CONTEXTE: La croissance et la maturation des spermatozoïdes sont corrélées avec les niveaux d'expression de la protéine 1 riche en répétitions Leucine et contenant des répétitions WD (LRWD1), une protéine largement exprimée dans les testicules humains. La diminution du niveau cellulaire en LRWD1 a été liée à une réduction de la croissance et des mitoses cellulaires, et à une augmentation des taux d'atrophie des microtubules cellulaires. Puisque la méthylation de l'ADN joue un rôle régulateur majeur dans l'expression des gènes, cette étude visait à explorer l'effet de la modulation de la méthylation de l'ADN sur les niveaux d'expression de LRWD1. RéSULTATS: Les résultats ont révélé la présence d'un îlot CpP de 298 pbs (-253~+45) sur le promoteur de LRWD1dans les cellules NT2/D1. L'hyperméthylation du promoteur de LRWD1 était liée à une réduction de l'activité de transcription dans les cellules NT2/D1, comme indiqué par l'analyse de l'expression d'un gène rapporteur codant pour la luciférase. L'activateur de méthylation, la floxuridine, a confirmé la diminution de l'activité transcriptionnelle du promoteur de LRWD1. D'autre part, la 5-Aza-2'-déoxycytidine (5-Aza-dc, inhibiteur de méthylation), a significativement augmenté l'activité du promoteur de LRWD1 et les niveaux d'expression de l'ARNm et des protéines. En outre, le statut de méthylation de l'ADN du promoteur de LRWD1 dans les échantillons d'ADN génomique de sperme humain a été analysé. Les résultats ont indiqué que la méthylation du promoteur de LRWD1 était corrélée à l'activité des spermatozoïdes. CONCLUSIONS: Ainsi, la régulation de l'expression LRWD1 est corrélée avec le statut de méthylation du promoteur de LRWD1, qui a joué un rôle important dans la modulation de la spermatogenèse, de la mobilité et de la vitalité des spermatozoïdes. Sur la base de ces résultats, le statut de méthylation du promoteur de LRWD1 peut servir de nouveau marqueur diagnostic moléculaire ou de cible thérapeutique dans l'infertilité masculine.

2.
Biochimie ; 158: 1-9, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30513371

RESUMO

SEPTIN12 (SEPT12) is a testis-enriched gene that is downregulated in the testis of infertile men with severe spermatogenic defects. While SEPT12 is involved in spermatogenic failure and sperm motility disorder, SEPT12 transcriptional regulation is still unknown. Here we report the promoter region of SEPT12 as a 245 bp segment upstream of the transcription start site. One androgen receptor (AR) and two estrogen receptor α (ERα) binding sites in this region were initially identified by bioinformatics prediction and confirmed by chromatin immunoprecipitation assay. Truncated ERα or AR binding sites decreased the promoter activity, which indicated that the ERα and AR are essential for the SEPT12 promoter. On the other hand, the promoter activity was enhanced by the treatment with 17ß-estradiol (E2) and 5α-dihydrotestosterone (5α-DHT). Thus, one androgen and two estrogen hormone responsive elements located in the promoter of SEPT12 gene can regulate SEPT12 expression. Two single nucleotide polymorphisms (SNPs), rs759992 T > C and rs3827527 C > T, were observed in the SEPT12 gene promoter region and were able to decrease the promoter activity. In conclusion, the current work identified the promoter of the human SEPT12 gene and provided key evidence about its transcriptional regulation via E2 and 5α-DHT. Since SEPT12 has an important role in spermatogenesis, SEPT12 expression analysis can be developed as a potential tool for the assessment of environmental or food pollution by hormones or for the evaluation of the risk of endocrine-disrupting chemicals (EDCs) in general.


Assuntos
Receptor alfa de Estrogênio/metabolismo , Infertilidade Masculina , Polimorfismo de Nucleotídeo Único , Receptores Androgênicos/metabolismo , Elementos de Resposta , Septinas , Testículo/metabolismo , Adulto , Receptor alfa de Estrogênio/genética , Humanos , Infertilidade Masculina/genética , Infertilidade Masculina/metabolismo , Infertilidade Masculina/patologia , Masculino , Receptores Androgênicos/genética , Septinas/biossíntese , Septinas/genética , Motilidade dos Espermatozoides , Espermatogênese/genética , Testículo/patologia
4.
Int J Oral Maxillofac Implants ; 32(1): e47-e54, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28095525

RESUMO

PURPOSE: To examine early bone tissue healing in dental implants incorporating StemBios cell therapy. MATERIALS AND METHODS: SLAffinity samples were examined by scanning electron microscopy and atomic force microscopy. The clinical trial comprised 11 patients, who each received a dental implant in the mandible. Only one of these 11 patients received StemBios cell therapy in combination with the dental implant. The patients continued to be observed over a 4-month period after implantation using computed tomography and resonance frequency analysis. RESULTS: It was found that StemBios cell therapy promoted bone tissue healing in the case of the treated dental implant. The data indicated that stress altered more smoothly and declined faster in the patient who received the StemBios cell therapy than those without StemBios cell therapy over 4 months. CONCLUSION: A dental implant with SLAffinity surface treatment, in combination with StemBios cell therapy, significantly promoted bone tissue healing, especially at early osseointegration compared with that of implants without StemBios cell therapy when monitored over a 4-month period.


Assuntos
Implantação Dentária Endóssea/métodos , Implantes Dentários , Osseointegração/fisiologia , Transplante de Células-Tronco/métodos , Adulto , Planejamento de Prótese Dentária , Feminino , Humanos , Masculino , Mandíbula/cirurgia , Microscopia Eletroquímica de Varredura , Pessoa de Meia-Idade , Propriedades de Superfície , Titânio , Cicatrização/fisiologia
5.
J Biomed Mater Res B Appl Biomater ; 105(4): 865-873, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-26821850

RESUMO

The purpose of the present study was to examine thermal damage and a sticking problem in the tissue after the use of a minimally invasive electrosurgical device with a nanostructured surface treatment that uses a femtosecond laser pulse (FLP) technique. To safely use an electrosurgical device in clinical surgery, it is important to decrease thermal damage to surrounding tissues. The surface characteristics and morphology of the FLP layer were evaluated using optical microscopy, scanning electron microscopy, and transmission electron microscopy; element analysis was performed using energy-dispersive X-ray spectroscopy, grazing incidence X-ray diffraction, and X-ray photoelectron spectroscopy. In the animal model, monopolar electrosurgical devices were used to create lesions in the legs of 30 adult rats. Animals were sacrificed for investigations at 0, 3, 7, 14, and 28 days postoperatively. Results indicated that the thermal damage and sticking situations were reduced significantly when a minimally invasive electrosurgical instrument with an FLP layer was used. Temperatures decreased while film thickness increased. Thermographic data revealed that surgical temperatures in an animal model were significantly lower in the FLP electrosurgical device compared with that in the untreated one. Furthermore, the FLP device created a relatively small area of thermal damage. As already mentioned, the biomedical nanostructured layer reduced thermal damage and promoted the antisticking property with the use of a minimally invasive electrosurgical device. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 865-873, 2017.


Assuntos
Eletrocirurgia/instrumentação , Lasers , Procedimentos Cirúrgicos Minimamente Invasivos/instrumentação , Nanoestruturas , Animais , Eletrocirurgia/métodos , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Ratos , Ratos Sprague-Dawley , Propriedades de Superfície
6.
J Biomed Mater Res B Appl Biomater ; 104(1): 96-105, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25647366

RESUMO

The objective of this study was to use surface functionalization to evaluate the antiadhesion property and thermal injury effects on the liver when using a novel electrosurgical unit with nanostructured-doped diamond-like carbon (DLC-Cu) thin films for tumor ablations. The physical and chemical properties of DLC-Cu thin films were characterized by contact angle goniometer, scanning electron microscope, and transmission electron microscope. Three-dimensional (3D) hepatic models were reconstructed using magnetic resonance imaging to simulate a clinical electrosurgical operation. The results indicated a significant increase of the contact angle on the nanostructured DLC-Cu thin films, and the antiadhesion properties were also observed in an animal model. Furthermore, the surgical temperature in the DLC-Cu electrosurgical unit was found to be significantly lower than the untreated unit when analyzed using 3D models and thermal images. In addition, DLC-Cu electrodes caused a relatively small injury area and lateral thermal effect. The results indicated that the nanostructured DLC-Cu thin film coating reduced excessive thermal injury and tissue adherence effect in the liver.


Assuntos
Eletrocirurgia/métodos , Neoplasias Hepáticas Experimentais/cirurgia , Membranas Artificiais , Aderências Teciduais/prevenção & controle , Animais , Humanos , Neoplasias Hepáticas Experimentais/metabolismo , Neoplasias Hepáticas Experimentais/patologia , Masculino , Ratos , Ratos Sprague-Dawley , Aderências Teciduais/metabolismo , Aderências Teciduais/patologia
7.
J Biomed Mater Res A ; 104(2): 397-405, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26418567

RESUMO

The purpose of the present study was to examine early tissue response and osseointegration in the animal model. The surface morphologies of SLAffinity were characterized using scanning electron microscopy and atomic force microscopy. The microstructures were examined by X-ray diffraction, and hardness was measured by nanoindentation. Moreover, the safety and toxicity properties were evaluated using computer-aided programs and cell cytotoxicity assays. In the animal model, implants were installed in the mandibular canine-premolar area of 12 miniature pigs. Each pig received three implants: machine, sandblasted, large grit, acid-etched, and SLAffinity-treated implants. The results showed that surface treatment did affect bone-to-implant contact (BIC) significantly. At 3 weeks, the SLAffinity-treated implants were found to present significantly higher BIC values than the untreated implants. The SLAffinity treatments enhanced osseointegration significantly, especially at early stages of bone tissue healing. As described above, the results of the present study demonstrate that the SLAffinity treatment is a reliable surface modification method.


Assuntos
Interface Osso-Implante , Implantes Experimentais , Mandíbula/metabolismo , Titânio , Animais , Cães , Mandíbula/patologia , Mandíbula/cirurgia , Camundongos , Células NIH 3T3 , Propriedades de Superfície , Suínos , Porco Miniatura
8.
Surg Endosc ; 30(7): 3035-49, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-26563510

RESUMO

BACKGROUND: Minimally invasive surgery is performed using an endoscope and other instruments including the electrosurgical units. However, concerns including surgical smoke, tissue sticking and thermal injury are remaining in electrosurgery. AIMS: Accordingly, a newly developed electrosurgical electrode coating with hydrogenated Cu-incorporated diamond-like carbon (DLC-Cu) film is purposed to improve the instrument performance. METHODS: The morphologies of DLC-Cu surfaces were characterized using transmission electron microscopy, scanning electron microscopy and atomic force microscopy. In this study, lesions were made on the liver lobes of adult rats, using a monopolar electrosurgical unit equipped with untreated stainless steel electrodes or treated-electrodes. Animals were killed for evaluations at 0, 3, 7 and 28 days postoperatively. RESULTS: Treated-electrodes generate less sticking tissues and adhesive blood cells. Thermography revealed that the surgical temperature in liver tissue from the treated-electrode was significantly lower than the untreated-electrode. Total injury area of livers treated with treated-electrodes was significantly smaller than the untreated-electrodes treatment. Moreover, treated-electrodes caused a relatively smaller area of lateral thermal injury, a smaller area of fibrotic tissue and a faster process of remodeling than the untreated-electrodes. Western blot analysis showed that rats treated with treated-electrode expressed lower levels of NF-κB, caspase-3 and MMP-9 than untreated-electrode. Immunofluorescence staining for caspase-3 revealed that the untreated-electrode caused more serious injury. CONCLUSIONS: This study reveals that the plating of electrodes with hydrogenated Cu-incorporated diamond-like carbon film is an efficient method for improving the performance of electrosurgical units, and should benefit wound remodeling. However, more tests must be carried out to confirm these promising findings in human patients.


Assuntos
Materiais Revestidos Biocompatíveis/química , Eletrodos , Eletrocirurgia/instrumentação , Nanoestruturas , Animais , Western Blotting , Queimaduras/patologia , Queimaduras/prevenção & controle , Carbono/química , Caspase 3/metabolismo , Cobre/química , Modelos Animais de Doenças , Fígado/cirurgia , Metaloproteinase 9 da Matriz/metabolismo , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Procedimentos Cirúrgicos Minimamente Invasivos/instrumentação , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , NF-kappa B/metabolismo , Ratos , Aço Inoxidável/química , Temperatura , Termografia
9.
Implant Dent ; 25(1): 63-73, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26473440

RESUMO

PURPOSE: The aim of the present study was to examine the osseointegration in low-density bone tissue for SLAffinity-treated implants with StemBios (SB) cell therapy. MATERIALS AND METHODS: The morphologies of SLAffinity-treated surfaces were characterized using scanning electron microscopy. In the animal model, implants were installed in the mandibular canine-premolar area of 12 miniature pigs. Each pig received 3 implants of machine, sand blasted, large grit, and acid etched, and SLAffinity-treated implants. In the clinical trial, 10 patients received 1 SLAffinity-treated implant in the maxilla in the posterior area and 1 patient with low bone tissue density received 2 SLAffinity-treated implants with SB cell therapy. Resonance frequency analysis and computed tomography were assessed monthly over the first 3 months after implant placement. RESULTS: The results demonstrated that surface treatment significantly affected early osseointegration in patients who received SB cell therapy. SB cell therapy transferred the stress caused by the implant more uniformly, and the stress decreased with healing time. SLAffinity-treated implants also proved clinically successful after the 3 months. CONCLUSION: The SLAffinity treatments enhanced osseointegration significantly, especially at early stages of bone tissue healing with SB cell therapy.


Assuntos
Implantação Dentária Endóssea/métodos , Implantes Dentários , Transplante de Células-Tronco/métodos , Adulto , Animais , Humanos , Microscopia Eletrônica de Varredura , Nanoestruturas , Propriedades de Superfície , Suínos , Porco Miniatura
10.
Implant Dent ; 24(4): 441-7, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25946663

RESUMO

OBJECTIVES: SLAffinity is the hybrid topography consisting of micropits and nanoporous TiO2 layers through electrochemical oxidation to mimic the natural bony environment. The aim of this study was to examine the rate of osseointegration in animal models and to further investigate the stability for implants with SLAffinity-treated surface in the clinical trial. MATERIALS AND METHODS: Implants were installed in the mandibular canine-premolar area of 12 miniature pigs. Each pig received 2 implants with the same shapes but with different chemical surfaces. In the clinical trial, 25 patients were included. Each patient received 1 SLAffinity-treated implant on the posterior area of either arch. Resonance frequency analysis and computed tomography were assessed weekly over the first 12 weeks after implant placement. RESULTS: The results found that surface treatment did affect the bone-to-implant contact (BIC) significantly. Comparison of BIC at 3 weeks in animal study showed that the SLAffinity-treated implants presented significantly higher values than machine surface implants. SLAffinity-treated implants also proved clinically successful through 12 months, ready for prosthodontic restoration. CONCLUSION: The effect of SLAffinity treatments enhanced osseointegration significantly, especially at early stages of bone healing. Clinical trial finding, furthermore, ensured that the SLAffinity treatment was a reliable surface modification alternative.


Assuntos
Implantação Dentária Endóssea/instrumentação , Implantação Dentária Endóssea/métodos , Implantes Dentários , Planejamento de Prótese Dentária , Osseointegração/fisiologia , Propriedades de Superfície , Adulto , Animais , Materiais Biocompatíveis , Densidade Óssea , Modelos Animais de Doenças , Feminino , Humanos , Implantes Experimentais , Masculino , Suínos , Porco Miniatura , Titânio , Tomografia Computadorizada por Raios X
11.
Ann Biomed Eng ; 43(10): 2383-93, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25851468

RESUMO

The purpose of the present study was to examine the extent of thermal injury in the brain after the use of a minimally invasive electrosurgical device with a nanostructured copper-doped diamond-like carbon (DLC-Cu) surface coating. To effectively utilize an electrosurgical device in clinical surgery, it is important to decrease the thermal injury to the adjacent tissues. The surface characteristics and morphology of DLC-Cu thin film was evaluated using a contact angle goniometer, scanning electron microscopy, and atomic force microscopy. Three-dimensional biomedical brain models were reconstructed using magnetic resonance images to simulate the electrosurgical procedure. Results indicated that the temperature was reduced significantly when a minimally invasive electrosurgical device with a DLC-Cu thin film coating (DLC-Cu-SS) was used. Temperatures decreased with the use of devices with increasing film thickness. Thermographic data revealed that surgical temperatures in an animal model were significantly lower with the DLC-Cu-SS electrosurgical device compared to an untreated device. Furthermore, the DLC-Cu-SS device created a relatively small region of injury and lateral thermal range. As described above, the biomedical nanostructured film reduced excessive thermal injury with the use of a minimally invasive electrosurgical device in the brain.


Assuntos
Encéfalo/cirurgia , Eletrocirurgia/instrumentação , Modelos Biológicos , Nanoestruturas , Procedimentos Neurocirúrgicos/instrumentação , Animais , Eletrocirurgia/métodos , Microscopia Eletrônica de Varredura , Procedimentos Neurocirúrgicos/métodos , Ratos , Ratos Sprague-Dawley , Propriedades de Superfície
12.
J Mater Sci Mater Med ; 26(2): 77, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25631273

RESUMO

The aim of the present study was to investigate the thermal injury in the liver after a minimally invasive electrosurgery technique with a copper-doped diamond-like carbon (DLC-Cu) surface coating. To effectively utilize electrosurgery in a clinical caner setting, it is necessary to suppress the thermal injury to adjacent tissues. The surface morphologies of DLC-Cu thin films were characterized using scanning electron microscopy and transmission electron microscopy. Three-dimensional liver models were reconstructed using magnetic resonance imaging to simulate the electrosurgical procedure. Our results indicated that the temperature decreased significantly when minimally electrosurgery with nanostructured DLC-Cu thin films was used, and that it continued to decrease with increasing film thickness. In an animal model, thermography revealed that the surgical temperature was significantly lower in the minimally invasive electrosurgery with DLC-Cu thin film (DLC-Cu-SS) compared to untreated electrosurgery. In addition, DLC-Cu-SS created a relatively small thermal injury area and lateral thermal effect. These results indicated that the biomedical nanostructure coating reduced excessive thermal injury, and uniformly distributed temperature in the liver.


Assuntos
Queimaduras por Corrente Elétrica/prevenção & controle , Eletrocirurgia/instrumentação , Hepatectomia/instrumentação , Fígado/cirurgia , Procedimentos Cirúrgicos Minimamente Invasivos/instrumentação , Nanotecnologia/instrumentação , Animais , Queimaduras por Corrente Elétrica/etiologia , Queimaduras por Corrente Elétrica/patologia , Eletrocirurgia/efeitos adversos , Transferência de Energia , Desenho de Equipamento , Análise de Falha de Equipamento , Hepatectomia/efeitos adversos , Temperatura Alta , Fígado/lesões , Fígado/patologia , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/cirurgia , Procedimentos Cirúrgicos Minimamente Invasivos/efeitos adversos , Nanodiamantes/química , Ratos Sprague-Dawley , Condutividade Térmica , Cicatrização
13.
J Biomed Mater Res A ; 103(1): 269-75, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24648307

RESUMO

The purpose of this research was to investigate stresses resulting from different thicknesses and compositions of hydrogenated Cu-incorporated diamond-like carbon (a-C:H/Cu) films at the interface between vascular stent and the artery using three-dimensional reversed finite element models (FEMs). Blood flow velocity variation in vessels with plaques was examined by angiography, and the a-C:H/Cu films were characterized by transmission electron microscopy to analyze surface morphology. FEMs were constructed using a computer-aided reverse design system, and the effects of antibacterial nanostructured composite films in the stress field were investigated. The maximum stress in the vascular stent occurred at the intersections of net-like structures. Data analysis indicated that the stress decreased by 15% in vascular stents with antibacterial nanostructured composite films compared to the control group, and the stress decreased with increasing film thickness. The present results confirmed that antibacterial nanostructured composite films improve the biomechanical properties of vascular stents and release abnormal stress to prevent restenosis. The results of the present study offer the clinical benefit of inducing superior biomechanical behavior in vascular stents.


Assuntos
Antibacterianos/administração & dosagem , Hemodinâmica , Nanoestruturas , Stents , Fenômenos Biomecânicos , Análise de Elementos Finitos , Humanos , Imageamento por Ressonância Magnética , Microscopia Eletrônica de Transmissão
14.
Implant Dent ; 23(6): 659-64, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25379663

RESUMO

OBJECTIVE: The purpose of this study was to investigate osseointegration and bone stress resulted during the first 3 months after the installation of functional implants modified with bioactive oxide. METHODS: Several studies have investigated finite element models for dental implants; however, only a few have examined a model for the implants during different stages of osseointegration. In this study, mandible models were reconstructed using computer tomographic data, and bone qualities and stress distributions were investigated as well. RESULTS: Bone quality increased rapidly within the 3-month bone healing time. Data analysis indicated that the bone stresses increased with the progress of osseointegration, and the maximum stresses were obtained at the position around the first screw. CONCLUSION: The results confirmed that functional films could improve the biomechanical properties of the implants and promote the initial bone stability. Furthermore, potential clinical benefit can be obtained due to the inducing superior biomechanical behavior in dental implants.


Assuntos
Densidade Óssea/fisiologia , Implantes Dentários , Osseointegração/fisiologia , Óxidos/farmacologia , Fenômenos Biomecânicos , Feminino , Análise de Elementos Finitos , Seguimentos , Humanos , Imageamento Tridimensional , Masculino , Propriedades de Superfície , Fatores de Tempo , Titânio/farmacologia , Tomografia Computadorizada por Raios X , Cicatrização/fisiologia
15.
J Biomed Mater Res A ; 101(4): 1195-200, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23349074

RESUMO

The purpose of this study was to investigate stresses resulting from different thicknesses of hydroxyapatite- and titanium dioxide (TiO(2))-treated layers at the interface between temporomandibular joint (TMJ) implants and bones using three-dimensional finite element models. For ensuring osseointegration of implant treatment, one must examine the stresses of interface between implant and bone tissue. Treated layers on TMJ implants are a very important factor in clinical application. Several studies have investigated finite element models for TMJs, but few have examined a model for TMJ implants with treated layers. In this study, TMJ models were reconstructed using computer tomography data, and the effects of treated layer thickness on the stress field during jaw movement were investigated; this index has not yet been reported with respect to TMJ implant. The maximum stresses in the bone occurred at the position of the first screw. Data analysis indicated a greater decrease in this stress in the case of using TMJ implants with TiO(2)-treated layers, and the stresses decreased with increasing layer thicknesses. Results confirmed that the treated layers improve biomechanical properties of the TMJ implants and release abnormal stress concentration in them. The results of our study offer the potential clinical benefit of inducing superior biomechanical behavior in TMJ implants.


Assuntos
Durapatita , Modelos Biológicos , Osseointegração , Próteses e Implantes , Estresse Mecânico , Articulação Temporomandibular , Titânio , Humanos
16.
J Biomed Mater Res A ; 101(4): 1158-64, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23065706

RESUMO

The objective of this study was to investigate the stress distributions of a surface-treated dental implant and bone tissue under physiological loading. For ensuring success of dental implant treatment, one must examine the magnitude and location of the maximum stresses. Stress analysis models were constructed from computer tomography data. Although several studies have investigated finite element models of dental implants, none have used an implant model with a nanoporous layer in a biomimetic geometrical mandible model. The novel implant surface used in this study, comprised of a microlevel porous containing a nanolevel porous structure, was complex and it was difficult to present due to the limitation of computer efficiency. However, this complex geometry was simplified using a film, to further investigate stresses resulting from 0 nm, 50 nm, 500 nm, 5 µm, and 50 µm surface treatment thicknesses. Results indicated that the stresses transferred more uniformly in implants with nanoporous surface treatments, and that the stresses decreased with increasing layer thickness. Our study showed that this could be potentially beneficial for understanding the stress properties of surface-treated layers for dental implants.


Assuntos
Remodelação Óssea , Implantes Dentários , Planejamento de Prótese Dentária , Osseointegração , Estresse Mecânico , Humanos , Porosidade , Tomografia Computadorizada por Raios X
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