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1.
Bioorg Med Chem Lett ; 27(20): 4682-4686, 2017 10 15.
Artículo en Inglés | MEDLINE | ID: mdl-28919340

RESUMEN

Twenty-five novel pregnenolone/2-cyanoacryloyl conjugates (6-30) were designed and prepared, with the aim of developing novel anticancer drugs with dual NF-κB inhibitory and anti-proliferative activities. Compounds 22 and 27-30 showed inhibition against TNF-α-induced NF-κB activation in luciferase assay, which was confirmed by Western blotting. Among them, compound 30 showed potent NF-κB inhibitory activity (IC50=2.5µM) and anti-proliferative against MCF-7, A549, H157, and HL-60 cell lines (IC50=6.5-36.2µM). The present study indicated that pregnenolone/2-cyanoacryloyl conjugate I can server asa novel scaffold for developing NF-κB inhibitors and anti-proliferative agents in cancer chemotherapy.


Asunto(s)
Antineoplásicos/síntesis química , Cianoacrilatos/química , Diseño de Fármacos , FN-kappa B/metabolismo , Pregnenolona/química , Células A549 , Antineoplásicos/farmacología , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Ensayos de Selección de Medicamentos Antitumorales , Células HL-60 , Humanos , Células MCF-7 , FN-kappa B/antagonistas & inhibidores , Relación Estructura-Actividad
2.
BMC Infect Dis ; 15: 156, 2015 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-25888020

RESUMEN

BACKGROUND: The role of single nucleotide polymorphisms (SNPs) of interleukin (IL)-28B in predicting therapeutic response of pegylated interferon (peg-IFN) plus ribavirin (PR) for genotype 1 infected chronic hepatitis C patients with advanced fibrosis (AF) is limited. The aim of this study is to assess its role in predicting sustained virologic responses (SVR) to treatment. METHODS: Forty-two patients with biopsy proven hepatitis C virus (HCV) related AF (group A; Ishak fibrosis score, ≥4) and 126 sex- and HCV genotype-matched patients without AF (group B; Ishak fibrosis score, ≤3) were recruited into study. All patients received PR therapy for 24 weeks. Baseline and on-treatment clinical, virological and host factors were evaluated for treatment efficacy. RESULTS: The SVR rate was significantly lower in group A than group B patients with genotype 1 infection (24% vs. 53.3%; p=0.011). However, it was similar in those with genotype non-1 infection (76.5% vs. 76.5%; p=1.0). IL-28B rs8099917 genotype TT is the strongest predictor for SVR in genotype 1 infection. Patients who had TT genotype and achieved RVR in group A had similar SVR rates with those in group B (44.4% vs. 53.3%; p=0.614). One third of patients in group A developed hematological adverse effects and had required modified doses during antiviral therapy. CONCLUSIONS: In HCV genotype 1 infected AF receiving 24 weeks of PR treatment, patients with IL28B rs8099917 genotype TT, achieving RVR had similar SVR rate with those without AF. In contrast, patients with IL-28B rs8099917 non-TT genotype without achieving RVR are suggested to stop therapy.


Asunto(s)
Antivirales/uso terapéutico , Hepacivirus/genética , Hepatitis C Crónica/tratamiento farmacológico , Interleucinas/genética , Cirrosis Hepática/patología , Antivirales/administración & dosificación , Estudios de Casos y Controles , Quimioterapia Combinada , Femenino , Genotipo , Hepatitis C Crónica/genética , Hepatitis C Crónica/patología , Hepatitis C Crónica/virología , Humanos , Interferón-alfa/administración & dosificación , Interferón-alfa/uso terapéutico , Interferones , Cirrosis Hepática/genética , Masculino , Persona de Mediana Edad , Polietilenglicoles/administración & dosificación , Polietilenglicoles/uso terapéutico , Polimorfismo de Nucleótido Simple , Valor Predictivo de las Pruebas , Proteínas Recombinantes/administración & dosificación , Proteínas Recombinantes/uso terapéutico , Ribavirina/administración & dosificación , Ribavirina/uso terapéutico , Índice de Severidad de la Enfermedad , Insuficiencia del Tratamiento , Carga Viral
3.
Int J Biol Macromol ; 261(Pt 2): 129831, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38302026

RESUMEN

The primary purpose of this work is to study the fabrication of a flexible natural cellulosic fiber composite. In this respect, natural cellulosic fiber was obtained by modified poplar wood fiber through sodium hydroxide (NaOH) and γ-Aminopropyl Triethoxysilan. Then, the composites were fabricated by hot-pressing the modified wood fibers and polyurethane following characterization. Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and scanning electron microscope (SEM) observation results confirmed that some of the hemicellulose and lignin were removed from wood fibers after NaOH modification and successfully grafted with alkoxy structures after KH550 modification. NaOH&KH550 modification improved the interfacial compatibility between poplar wood fibers and polyurethane. The flexibility of the composites was improved (the slenderness value was reduced by 113 %), allowing flexible deformations such as bending, twisting, and knotting. In addition, thermal stability, tensile strength (increased by 105 %), elongation at the break (increased by 125 %), and water resistance were increased. This flexible natural cellulosic fiber composite is expected to be applied in the veneering of curved materials and special-shaped structure furniture, providing a theoretical basis for improving the added value of wood-based composites.


Asunto(s)
Lignina , Poliuretanos , Propilaminas , Silanos , Hidróxido de Sodio , Lignina/química , Resistencia a la Tracción
4.
J Dent Sci ; 19(2): 919-928, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38618085

RESUMEN

Background/purpose: The chemo-mechanical caries-removal technique is known to offer advantages of selective dentin caries treatment while leaving healthy dental tissues intact. However, current sodium hypochlorite based reagents usually excessively damage dentin collagen. Therefore, the purpose of this study was to develop a novel chemo-mechanical caries-removal system to preserve the collagen network for subsequent prosthetic restorations. Materials and methods: The calfskin-derived collagen was chosen as a model system to investigate the dissolution behavior of collagen under different operating conditions of chemical-ultrasonic treatment systems. The molecular weight, triple-helix structure, the morphology, and functional group of collagen after treatment were investigated. Results: Various concentrations of sodium hypochlorite or zinc chloride together with ultrasonic machinery were chosen to investigate. The outcomes of circular dichroism (CD) spectra demonstrated stability of the triple-helix structure after treatment of a zinc chloride solution. In addition, two apparent bands at molecular weights (MWs) of 130 and 121 kDa evidenced the stability of collagen network. The positive 222 nm and 195 nm negative CD absorption band indicated the existence of a triple-helix structure for type I collagen. The preservation of the morphology and functional group of the collagen network on the etched dentin surface were investigated by in vitro dentin decalcification model. Conclusion: Unlike NaOCl, the 5 wt% zinc chloride solution combined with ultra-sonication showed dissolution rather than denature as well as degradation of the dentin collagen network. Additional in vivo evaluations are needed to verify its usefulness in clinical applications.

5.
Int J Biol Macromol ; 253(Pt 5): 127265, 2023 Dec 31.
Artículo en Inglés | MEDLINE | ID: mdl-37802453

RESUMEN

Incorporation of natural fibers into polylactic acid (PLA) provides a feasible pathway to improve the performance of PLA with a low environmental impact. However, the insufficient interfacial adhesion between fiber and matrix limits the reinforcement efficiency of fiber and final mechanical properties of the biocomposites. Herein we reported an efficient method to simultaneously enhance interfacial interaction, crystallization and mechanical performance of PLA-based biocomposites via combination of wood fiber (WF) and a self-assembly nucleating agent (TMC-300). The interactions between WF and TMC-300 and its influence on PLA, including interfacial crystal morphology, crystallization behavior, and mechanical performance were studied. The results showed that TMC-300 could self-assemble into dendritic-like structure on WF surface driven by hydrogen bonding, inducing the epitaxial crystallization of PLA. This unique interfacial crystallization integrated PLA matrix with WF, resulting in better interfacial adhesion. Under the optimal TMC-300 content (0.5 wt%), the flexural strength and notched impact strength of PLA composites increased by 10 % and 69 % compared with neat PLA, respectively. Additionally, TMC-300 and WF synergistically functioned as effective nucleating agents, which significantly accelerated the crystallization rate and improved the crystallinity of PLA. This work provides a new insight into the enhancement of interfacial bonding in natural fiber/PLA biocomposites.


Asunto(s)
Poliésteres , Madera , Cristalización , Poliésteres/química
6.
Bioact Mater ; 21: 175-193, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36093328

RESUMEN

Mandibular defect becomes a prevalent maxillofacial disease resulting in mandibular dysfunctions and huge psychological burdens to the patients. Considering the routine presence of oral contaminations and aesthetic restoration of facial structures, the current clinical treatments are however limited, incapable to reconstruct the structural integrity and regeneration, spurring the need for cost-effective mandibular tissue engineering. Hydrogel systems possess great merit for mandibular reconstruction with precise involvement of cells and bioactive factors. In this review, current clinical treatments and distinct mode(s) of mandible formation and pathological resorption are summarized, followed by a review of hydrogel-related mandibular tissue engineering, and an update on the advanced fabrication of hydrogels with improved mechanical property, antibacterial ability, injectable form, and 3D bioprinted hydrogel constructs. The exploration of advanced hydrogel systems will lay down a solid foundation for a bright future with more biocompatible, effective, and personalized treatment in mandibular reconstruction.

7.
Adv Sci (Weinh) ; 10(22): e2300897, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37218542

RESUMEN

The knowledge of osteoarthritis (OA) has nowadays been extended from a focalized cartilage disorder to a multifactorial disease. Although recent investigations have reported that infrapatellar fat pad (IPFP) can trigger inflammation in the knee joint, the mechanisms behind the role of IPFP on knee OA progression remain to be defined. Here, dysregulated osteopontin (OPN) and integrin ß3 signaling are found in the OA specimens of both human and mice. It is further demonstrated that IPFP-derived OPN participates in OA progression, including activated matrix metallopeptidase 9 in chondrocyte hypertrophy and integrin ß3 in IPFP fibrosis. Motivated by these findings, an injectable nanogel is fabricated to provide sustained release of siRNA Cd61 (RGD- Nanogel/siRNA Cd61) that targets integrins. The RGD- Nanogel possesses excellent biocompatibility and desired targeting abilities both in vitro and in vivo. Local injection of RGD- Nanogel/siRNA Cd61 robustly alleviates the cartilage degeneration, suppresses the advancement of tidemark, and reduces the subchondral trabecular bone mass in OA mice. Taken together, this study provides an avenue for developing RGD- Nanogel/siRNA Cd61 therapy to mitigate OA progression via blocking OPN-integrin ß3 signaling in IPFP.


Asunto(s)
Cartílago Articular , Osteoartritis de la Rodilla , Humanos , Ratones , Animales , Integrina beta3 , Nanogeles , Osteopontina , Articulación de la Rodilla , Tejido Adiposo , ARN Interferente Pequeño/genética , Oligopéptidos
8.
Pharmaceutics ; 14(11)2022 Nov 07.
Artículo en Inglés | MEDLINE | ID: mdl-36365215

RESUMEN

Reconstruction of a mandibular defect is challenging, with high expectations for both functional and esthetic results. Bone morphogenetic protein-2 (BMP-2) is an essential growth factor in osteogenesis, but the efficacy of the BMP-2-based strategy on the bone regeneration of mandibular defects has not been well-investigated. In addition, the underlying mechanisms of BMP-2 that drives the bone formation in mandibular defects remain to be clarified. Here, we utilized BMP-2-loaded hydrogel to augment bone formation in a critical-size mandibular defect model in rats. We found that implantation of BMP-2-loaded hydrogel significantly promoted intramembranous ossification within the defect. The region with new bone triggered by BMP-2 harbored abundant CD31+ endomucin+ type H vessels and associated osterix (Osx)+ osteoprogenitor cells. Intriguingly, the new bone comprised large numbers of skeletal stem cells (SSCs) (CD51+ CD200+) and their multi-potent descendants (CD51+ CD105+), which were mainly distributed adjacent to the invaded blood vessels, after implantation of the BMP-2-loaded hydrogel. Meanwhile, BMP-2 further elevated the fraction of CD51+ CD105+ SSC descendants. Overall, the evidence indicates that BMP-2 may recapitulate a close interaction between functional vessels and SSCs. We conclude that BMP-2 augmented coupling of angiogenesis and osteogenesis in a novel and indispensable way to improve bone regeneration in mandibular defects, and warrants clinical investigation and application.

9.
Colloids Surf B Biointerfaces ; 203: 111723, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33839474

RESUMEN

Although the biomedical sciences have achieved tremendous success in developing novel approaches to managing prostate cancer, this disease remains one of the major health concerns among men worldwide. Liposomal formulations of single drugs have shown promising results in cancer treatment; however, the use of multi drugs has shown a better therapeutic index than individual drugs. The identification of cancer-specific receptors has added value to design targeted drug delivering nanocarriers. We have developed genistein and plumbagin co-encapsulating liposomes (∼120 nm) with PSMA specific antibodies to target prostate cancer cells selectively in this work. These liposomes showed >90 % decrease in PSMA expressing prostate cancer cell proliferation without any appreciable toxicity to healthy cells and human red blood cells. Release of plumbagin and genistein was found to decrease the expression of PI3/AKT3 signaling proteins and Glut-1 receptors (inhibited glucose uptake and metabolism), respectively. The decrease in migration potential of cells and induced apoptosis established the observed anti-proliferative effect in prostate cancer cell lines. The discussed strategy of developing novel, non-toxic, and PSMA specific antibody conjugated liposomes carrying genistein and plumbagin drugs may also be used for encapsulating other drugs and inhibit the growth of different types of cancers.


Asunto(s)
Glutamato Carboxipeptidasa II , Neoplasias de la Próstata , Apoptosis , Línea Celular Tumoral , Genisteína/farmacología , Humanos , Liposomas , Masculino , Naftoquinonas , Neoplasias de la Próstata/tratamiento farmacológico
10.
Materials (Basel) ; 13(2)2020 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-31936078

RESUMEN

The objective of this study was to evaluate the antibacterial efficacy against Enterococcus faecalis and Streptococcus mutans and in vivo toxicity using embryonic zebrafish assays of sodium hypochlorite (NaOCl) and electrolyzed oxidizing (EO) water (containing hypochlorous acid (HOCl))-based root canal irrigating solutions. METHODOLOGY: Using 100 µL microbial count of 1 × 108 cfu/mL Enterococcus faecalis to mix with each 10 mL specimen of NaOCl or HOCl for designed time periods. The above protocol was also repeated for Streptococcus mutans. The concentration of viable microorganisms was estimated based on each standardized inoculum using a plate-count method. Zebrafish embryo assays were used to evaluate acute toxicity. RESULTS: All the HOCl or NaOCl treatment groups showed > 99.9% antibacterial efficacy against Enterococcus faecalis and Streptococcus mutans. Zebrafish embryos showed almost complete dissolution in 1.5% NaOCl within 5 min. Both survival rates after being treated with 0.0125% and 0.0250% HOCl for 0.5 min or 1.0 min were similar to that of E3 medium. CONCLUSIONS: Both NaOCl and HOCl revealed similar antibacterial efficacy (> 99.9%) against Enterococcus faecalis and Streptococcus mutans. While 1.5% NaOCl fully dissolved the Zebrafish embryos, both 0.0125% and 0.0250% HOCl showed little in vivo toxicity, affirming its potential as an alternative irrigation solution for vital pulp therapy.

11.
Materials (Basel) ; 13(19)2020 Sep 26.
Artículo en Inglés | MEDLINE | ID: mdl-32993124

RESUMEN

The objective of this study was to verify the feasibility of electrolyzed oxidizing (EO) water as a mouthwash through the evaluation of its in vivo toxicity by embryonic zebrafish and antimicrobial efficacy against Streptococcus mutans (S. mutans). METHODOLOGY: Each 1.5-3.0 g of sodium chloride (NaCl), sodium bromide (NaBr), or calcium chloride (CaCl2) were added into an electrolyzer with 300 mL of DD water to produce electrolyzed oxidizing (EO) water. A zebrafish embryo assay was used to evaluate acute toxicity of specimens. Antimicrobial property was conducted with 100 µL microbial count of 1 × 108 cfu/mL S. mutans to blend with each 10 mL specimen of chlorhexidine (CHX) gluconate or hypochlorous acid (HOCl) for various time points. The concentration of viable microorganisms was assessed according to individually standardized inoculum by a plate-count method. RESULTS: Among the EO water produced from NaCl, NaBr, and CaCl2, the EO water from NaCl showed a relatively low mortality rate of zebrafish embryos and was chosen for a detailed investigation. The mortality rates for the groups treated with EO water containing 0.0125% and 0.0250% HOCl were not statically different from those of a negative control, however the mortality rate was 66.7 ± 26.2% in 0.2% CHX gluconate for the same treatment time of 0.5 min. All of the HOCl or 2.0% CHX gluconate groups showed >99.9% antimicrobial effectiveness against S. mutans; while the 0.2% CHX gluconate group showed a bacterial reduction rate of 87.5% and 97.1% for treatment times of 0.5 min and 1.0 min, respectively. CONCLUSIONS: Except for the 0.2% CHX gluconate, all the HOCl specimens and 2.0% CHX gluconate revealed similar antimicrobial properties (>99.9%) against S. mutans. The EO water comprised of both 0.0125% and 0.0250% HOCl showed >99.9% antimicrobial efficacy but with little in vivo toxicity, illuminating the possibility as an alternative mouthwash for dental and oral care.

12.
Beijing Da Xue Xue Bao Yi Xue Ban ; 41(5): 525-30, 2009 Oct 18.
Artículo en Zh | MEDLINE | ID: mdl-19829667

RESUMEN

OBJECTIVE: To investigate the killing effect of nanoliposome encapsulated cisplatin (NLE-CDDP) on human osteosarcoma cell line Saos-2 and explore the distribution of platinum (Pt) in tumor-bearing mice. METHODS: Saos-2 cells were cultured at different concentrations of NLE-CDDP. MTT assay, inverted microscopic observation and flow cytometry assay(FCM)were used to observe the antiproliferative effect of NLE-CDDP on the human osteosarcoma cells. Antitumor effect of NLE-CDDP was determined using the xenografts models of human osteosarcoma cell Saos-2 in nude mice. The Pt concentration in the tissues of tumor-transplanted mice was determined by atomic spectrophotometer. RESULTS: When treated at different concentrations of NLE-CDDP for 24-96 hours, the survival rate of Saos-2 cells decreased significantly(P<0.05). At the same time point, the inhibitory effect of NLE-CDDP was stronger than that of CDDP;Degeneration and necrosis of Saos-2 cells increased; the apoptosis increased and the S phase reduced. This study demonstrated that NLE-CDDP had obvious anti-tumor activity. Within 1 hour of injection, in NLE-CDDP group plasma platinum concentration was 4.4-fold that in CDDP group; 2 hours later, platinum was not detected in the blood of CDDP group; 24 hours later, platinum still could be detected in NLE-CDDP group at 2.76 mumol/L. During the first hour after injection of NLE-CDDP, the platinum content of the kidney was 50% less than that of CDDP group. Platinum in NLE-CDDP group showed rapid higher accumulation in the liver, spleen and tumor compared with CDDP group, and within 24 hours platinum reached the peak concentration in the spleen. CONCLUSION: The antitumor efficacy of NLE-CDDP on Saos-2 tumor is higher than that CDDP alone, and its mechanism is delaying rapid clearance from circulation.


Asunto(s)
Neoplasias Óseas/patología , Cisplatino/farmacología , Liposomas , Nanopartículas , Osteosarcoma/patología , Animales , Antineoplásicos/administración & dosificación , Antineoplásicos/farmacocinética , Antineoplásicos/farmacología , Neoplasias Óseas/tratamiento farmacológico , Neoplasias Óseas/metabolismo , Línea Celular Tumoral , Cisplatino/administración & dosificación , Cisplatino/farmacocinética , Portadores de Fármacos , Femenino , Humanos , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Trasplante de Neoplasias , Osteosarcoma/tratamiento farmacológico , Osteosarcoma/metabolismo
13.
FEBS Open Bio ; 7(6): 747-758, 2017 06.
Artículo en Inglés | MEDLINE | ID: mdl-28593131

RESUMEN

Enterovirus 71 (EV71) is the major causative agent of hand-foot-and-mouth disease in young children and can cause severe cerebral and pulmonary complications and even fatality. This study aimed at elucidating whether and how EV71 infection is regulated by a cellular microRNA, miR-127-5p. We found that miR-127-5p can downregulate the expression of SCARB2, a main receptor of EV71, by targeting two potential sites in its 3' UTR region and inhibit EV71 infection. Meanwhile, miR-127-5p expression was upregulated during EV71 infection. Notably, transfecting cells with miR-127-5p mimics led to a significant decrease in viral replication, while inhibition of endogenous miR-127-5p facilitated viral replication. Furthermore, our evidence showed that miR-127-5p did not affect postentry viral replication. Taken together, these results indicated that miR-127-5p inhibited EV71 replication by targeting the SCARB2 mRNA.

14.
Materials (Basel) ; 10(3)2017 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-28772594

RESUMEN

INTRODUCTION: The objective of this in vitro study is to evaluate the effective and long-term occlusion of dentinal tubules using a novel calcium lactate phosphate (CLP) based desensitizing agent. METHODS: Dentin disks (n = 9) were pre-etched using 1 M lactic acid for 30 s and individually treated with Colgate® Pro-Relief™ paste, CLP paste, and double distilled water (ddH2O) by a rubber-cupped handpiece. Dentin disks were analyzed under optical micrographs for pre-treatment, directly after treatment, and 14 days post-treatment. One-way ANOVA and post-hoc Tukey's test were used to determine whether there were any statistically significant differences in dentinal tubule diameter. RESULTS: A significant decrease occurred in the mean tubule diameter for dentin disks treated with CLP paste. A decrease was observed from 3.52 ± 0.83 µm to 2.62 ± 0.42 µm right after treatment, further decreasing to 1.71 ± 0.45 µm after immersion in artificial saliva for 14 days (p < 0.05). CONCLUSIONS: The results suggest that the CLP based desensitizing paste has remineralization properties and provides instant and lasting effectiveness in dentinal tubule occlusion.

15.
Biomed Mater ; 4(1): 015004, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-18981540

RESUMEN

Corrosion behaviour of biomedical alloys is generally determined in mineral electrolytes: unbuffered NaCl 0.9% (pH 7.4) or artificial saliva (pH 6.8). The assays with exclusive utilization of these electrolytes are of low relevance for the biological condition, to which the alloys will be exposed once implanted in the human organism. As an approach to the biological situation regarding the interaction of proteins, electrolytes and metals, we added the RPMI cell culture medium containing foetal calf serum as a biological electrolyte (pH 7.0). The analysis of corrosion behaviour was also performed in the presence of human lymphoid cells (CEM). The rest potential (Er) and the global polarization were determined on cp-Ti, micro-arc oxidized cp-Ti (MAO-Ti), four different Ti-alloys (Ti6Al4V, Ti12Zr, Ti(AlMoZr), Ti(NbTaZr)) and 316L stainless steel. The 316L exhibited an appropriate Er and a good passive current density (Ip), but a high corrosion potential (Ec) and a very low breakdown potential (Eb) in all electrolytes. All Ti-alloys exhibited a much better electrochemical behaviour: better Er and Ec and very high Eb. No significant differences of the above parameters existed between the Ti-alloys, except for Zr-containing alloys that showed better corrosion behaviour. A remarkable difference, however, was stated with respect to the electrolytes. NaCl 0.9% induced strong variations between the Ti-alloys. More homogeneous results were obtained with artificial saliva and RPMI medium, which induced a favourable Ec and an increased Ip. The presence of cells further decreased these values. The unbuffered NaCl solution seems to be less appropriate for the analysis of corrosion of metals. Additional in vitro biological assessments with CEM cell suspensions and MC3T3-E1 osteoblasts confirmed the advantages of the Ti(AlMoZr) and Ti(NbTaZr) alloys with an improved cell proliferation and vitality rate.


Asunto(s)
Aleaciones/química , Materiales Biocompatibles/química , Linfocitos/química , Linfocitos/fisiología , Osteoblastos/química , Osteoblastos/fisiología , Titanio/química , Animales , Línea Celular , Proliferación Celular , Supervivencia Celular , Corrosión , Linfocitos/citología , Ensayo de Materiales , Ratones , Osteoblastos/citología
16.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 38(6): 414-6, 2003 Nov.
Artículo en Zh | MEDLINE | ID: mdl-14703470

RESUMEN

OBJECTIVE: To reveal the stress distribution in the superstructure of fixed bridge supported by tooth-implant in the process of mastication for improvement of denture design. METHODS: The stress distribution and displacement of the superstructure were studied and analyzed by means of CT Scan, CAD and three-dimensional finite element when various loads were applied. RESULTS: (1) The stress distribution in abutments under oblique loads at forty-five degrees was uneven and the peak value was 4 - 6 times higher than that under vertical loads. Stress concentration occurred with significant compressive stress. (2) Compressive stress widely distributed in the middle area of occlusal surface of pontic, whose peak value under concentrated loads was significantly higher than that under disperse loads. The loading direction had no effect on the stress concentration. (3) The maximum displacement of implant abutment in medial-distal direction was greater than that of the neck of nature tooth. CONCLUSIONS: The mechanic complications of superstructure could be prevented by reducing oblique loads and concentrated ones. It is certain that the further improvements of curve-resistance of pontics and press-resistance of abutments are available.


Asunto(s)
Implantes Dentales , Análisis del Estrés Dental , Análisis de Elementos Finitos , Dentadura Parcial Fija , Humanos
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