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1.
J Biomed Mater Res B Appl Biomater ; 112(7): e35445, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38946669

RESUMO

In this study, we evaluated the drug release behavior of diameter customized TiO2 nanotube layers fabricated by anodization with various applied voltage sequences: conventional constant applied potentials of 20 V (45 nm) and 60 V (80 nm), a 20/60 V stepped potential (50 nm [two-diameter]), and a 20-60 V swept potential (49 nm [full-tapered]) (values in parentheses indicate the inner tube diameter at the top part of nanotube layers). The structures of the 50 nm (two-diameter) and 49 nm (full-tapered) samples had smaller inner diameters at the top part of nanotube layers than that of the 80 nm sample, while the outer diameters at the bottom part of nanotube layers were almost the same size as the 80 nm sample. The 80 nm sample, which had the largest nanotube diameter and length, exhibited the greatest burst release, followed by the 50 nm (two-diameter), 49 nm (full-tapered), and 45 nm samples. The initial burst released drug amounts and release rates from the 50 nm (two-diameter) and 49 nm (full-tapered) samples were significantly suppressed by the smaller tube top. On the other hand, the largest proportion of the slow released drug amount to the total released drug amount was observed for the 50 nm (two-diameter) sample. Thus, 50 nm (two-diameter) achieved suppressed initial burst release and large storage capacity. Therefore, this study has, for the first time, applied TiO2 nanotube layers with modulated diameters (two-diameter and full-tapered) to the realization of a localized drug delivery system (LDDS) with customized drug release properties.


Assuntos
Nanotubos , Titânio , Titânio/química , Nanotubos/química , Sistemas de Liberação de Medicamentos , Liberação Controlada de Fármacos , Tamanho da Partícula
2.
Crohns Colitis 360 ; 6(2): otae035, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38827168

RESUMO

Background: Crohn's disease (CD) is an immune-mediated inflammatory disorder of the gastrointestinal tract with perianal disease being one of the challenging possible manifestations. Here, we report, an ad hoc analysis of the safety and effectiveness of 1-year use of ustekinumab (UST) for CD in patients with perianal manifestations using post-marketing surveillance (PMS) data in Japan. Methods: Among 341 patients enrolled in the PMS, 229 and 224 patients who had baseline Crohn's Disease Activity Index (CDAI) data used for evaluating perianal manifestations were included in the safety and efficacy analysis sets, respectively. Incidence of adverse drug reactions, clinical remission, the mean or its change in CDAI scores, and CDAI items were evaluated through week 52 in the presence or absence of perianal manifestations at baseline. The prevalence of perianal manifestations was also described. Results: Comparing patients with and without baseline perianal manifestations at week 52, there was no difference in ADR incidence (9.1% [n = 66] vs. 15.3% [n = 163]), no difference in clinical remission (68.3% vs. 59.9%; P = 0.269), and decreased mean change of CDAI score (-82.9 [n = 60] vs. -68.8 [n = 137]). The proportion of patients with perianal manifestations decreased after UST treatment in both biologics-naïve patients (23.5% [n = 4/17]) and patients who had received biologics (35.0% [n = 14/40]) at week 52. Conclusions: In Japanese clinical practice, UST is safe and effective in CD patients with and without perianal manifestations. The therapy might be also beneficial in those with manifestations regardless of prior use of other biologics.

3.
Mod Rheumatol ; 2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38780239

RESUMO

OBJECTIVES: To assess the efficacy of golimumab (GLM) in patients with poor prognostic factors (PPFs). METHODS: This is a post-hoc analysis of GO-FORTH phase 2/3 study. Cluster analysis was used to determine a patient population with high-risk patterns based on seven PPFs suggested by EULAR recommendations and limited physical function. Radiographic progression, disease activity, and physical function and associated factors were evaluated over 52 weeks. RESULTS: Overall, 261 RA patients were classified into three clusters characterised by high disease activity, high CRP levels, and limited physical function at baseline. GLM showed suppression of progressive modified total sharp score (mTSS) and decreases in Disease Activity Score 28‒joint counts with erythrocyte sedimentation rate and Health Assessment Questionnaire‒Disease Index, in all the clusters. In cluster C that showed almost all the PPF-characteristics, a higher rate of ΔmTSS≤0 was observed in GLM 100 mg group than in GLM 50 mg group (63.9% vs 46.5%). CRP concentration and physical limitation were associated with radiographic progression of cluster C in GLM treatment. CONCLUSIONS: GLM was effective in RA patients in a subpopulation at high risk of PPF in GO-FORTH study. A dose of 100 mg may be more beneficial in preventing radiographic progression in this population. Short title: Impact of poor prognostic factors on GLM efficacy.

4.
J Dermatol ; 51(6): 779-790, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38747075

RESUMO

A 52-week postmarketing surveillance study was initiated to evaluate the safety and effectiveness of guselkumab, a human anti-interleukin 23 subunit p19 monoclonal antibody, in Japanese patients with psoriasis vulgaris, psoriatic arthritis, generalized pustular psoriasis, and erythrodermic psoriasis in real-world practice. Here, we report results of the 20-week interim analysis of the ongoing postmarketing surveillance study. Patients who received guselkumab between May 2018 (the date of commercial launch in Japan) and October 2020 were registered in this study. In total, 411 and 245 patients were included in the safety and effectiveness analysis sets, respectively. Adverse drug reactions (ADRs) occurred in 6.6% (27 of 411) and serious ADRs in 2.2% (nine of 411) of patients. The most frequent ADRs by System Organ Class were "Infections and infestations" (2.4%), with nasopharyngitis being the most frequently observed ADR (0.7%). The mean Psoriasis Area Severity Index score decreased from 11.6 at baseline to 6.5 at week 4 and 2.2 at week 20, with improvements achieving statistical significance at each time point. Clinical Global Impression, Dermatology Life Quality Index, and Nail Psoriasis Severity Index outcomesalso showed substantial improvements. Our findings demonstrate that guselkumab is well tolerated and effective in Japanese patients with psoriasis through 20 weeks of treatment in real-world clinical practice, showing significant effectiveness observed as early as 4 weeks. The study was officially registered with the University Hospital Medical Information Network Clinical Trials Registry with the identifier UMIN000032969.


Assuntos
Anticorpos Monoclonais Humanizados , Vigilância de Produtos Comercializados , Psoríase , Índice de Gravidade de Doença , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Anticorpos Monoclonais Humanizados/efeitos adversos , Anticorpos Monoclonais Humanizados/administração & dosagem , População do Leste Asiático , Subunidade p19 da Interleucina-23/antagonistas & inibidores , Subunidade p19 da Interleucina-23/imunologia , Japão , Nasofaringite/induzido quimicamente , Nasofaringite/epidemiologia , Psoríase/tratamento farmacológico , Qualidade de Vida , Resultado do Tratamento
5.
Intest Res ; 2024 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-38311715

RESUMO

Background/Aims: A previous study demonstrated that half of patients started oral corticosteroids (OCS) for ulcerative colitis (UC) exacerbations at lower doses than recommended by Japanese treatment guidelines (initial OCS prednisolone equivalent dose, 30-40 mg). This may relate to physician's concern about infection, especially pneumonia including Pneumocystis jirovecii pneumonia (PJP), from high OCS doses. We assessed whether pneumonia incidence is increased with guideline-recommended OCS initial doses. Methods: This retrospective cohort study used the Japan Medical Data Center claims database (2012-2021). The whole cohort consisted of all UC patients who started OCS during the study period meeting the inclusion and exclusion criteria. The matched cohort was created by propensity score matching; the lower (initial OCS dose < 30 mg), guideline-recommended (30-40 mg), and higher groups ( > 40 mg) in a 2:2:1 ratio. Pneumonia incidence in the primary analysis was evaluated in the matched cohort. A Poisson regression model determined pneumonia-related risk factors in the whole cohort. Results: After screening, 3,349 patients comprised the whole cohort; 1,775 patients comprised the matched cohort (lower dose, n = 710; guideline-recommended dose, n = 710; higher dose, n = 355). The incidence of any pneumonia was low; no differences were observed in incidence rates across these dose subgroups. In total, 3 PJP cases were found in the whole cohort, but not detected in the matched cohort. Several risk factors for any pneumonia were identified, including age, higher comorbidities index, treatment in large facility and hospitalization. Conclusions: The incidence of pneumonia, including PJP, in UC patients was low across initial OCS dose treatment subgroups.

6.
Adv Ther ; 40(10): 4545-4560, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37572265

RESUMO

INTRODUCTION: Docetaxel is an established standard therapy after osimertinib and platinum-based doublet chemotherapy (Pt-doublet) for locally advanced or metastatic non-small cell lung cancer (NSCLC) with an epidermal growth factor receptor gene (EGFR) mutation. To facilitate future therapeutic developments in these patients after treatment with osimertinib and Pt-doublet, we estimated the outcomes of currently used post-treatment therapies. METHODS: Data of patients with NSCLC who received at least one medication after osimertinib and Pt-doublet between April 2008 and August 2021 were extracted from the Medical Data Vision claims database. The duration of treatment (DoT) (first treatment after osimertinib and Pt-doublet) and overall survival (OS) were estimated. The index date was the first day on which the medication was prescribed. RESULTS: In total, 731 patients (mean age 64 years) were screened. The most frequent post-treatments were docetaxel-based chemotherapy (30.2%), immune checkpoint inhibitor (ICI) alone or in combination (17.2%), first-/second-generation EGFR-tyrosine kinase inhibitors (16.7%), osimertinib (16.3%), and Pt-doublet (5.2%). The median DoT and OS (95% confidence interval) of all post-treatments were 3.5 (3.27, 3.77) and 10.3 (9.3, 12.1) months, respectively, reflecting the median DoT (3.8 months) and OS (10.0 months) of docetaxel-based chemotherapy. Among all post-treatment regimens, ICIs resulted numerically the shortest [2.77 (2.33, 3.00) months] and osimertinib the longest [4.40 (3.47, 5.67) months] median DoT. The median OS was shortest in patients post-treated with ICIs [7.07 (5.40, 9.90) months] and longest in patients rechallenged with Pt-doublet (12.27 months), followed by patients post-treated with osimertinib (11.70 months). In a subset analysis of patients who received first-line osimertinib and second-line Pt-doublet as well as Pt-doublet immediately after osimertinib, those post-treated with ICIs had the shortest median DoT. CONCLUSION: Given the limited real-world efficacy on EGFR-mutant NSCLC resistant to osimertinib and platinum-based chemotherapy, the development of more highly potent post-treatment therapies is warranted.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Humanos , Pessoa de Meia-Idade , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Genes erbB-1 , Docetaxel/uso terapêutico , Platina/uso terapêutico , Platina/efeitos adversos , Receptores ErbB , Resultado do Tratamento , Inibidores de Proteínas Quinases/uso terapêutico , Mutação
7.
Crohns Colitis 360 ; 5(1): otad001, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36777365

RESUMO

Background: To present the real-world evidence on the safety and effectiveness of ustekinumab (UST) through 52-week treatment for Crohn's disease (CD) under an analysis of post-market surveillance data in Japan. Methods: This prospective, post-marketing surveillance study was conducted in 341 patients from 91 medical facilities in Japan. Patients received UST 90 mg injected subcutaneously once every 12 weeks (or every 8 weeks if patients show weak effectiveness) after an induction dose given intravenously. Clinical response (100-point decrease in Crohn's Disease Activity Index [CDAI] score), clinical remission (CDAI score of <150), steroid-free clinical remission, C-reactive protein, endoscopy, physician global assessment, and adverse drug reactions (ADRs) were evaluated through 52 weeks. Results: The overall rate of clinical remission was 49.2% at week 8 and 56.0% at week 52. The rate of clinical remission in biologic-naive patients was 75.9% and 66.7% at weeks 8 and 52, respectively, whereas the rate in biologic-experienced patients was 41.4% and 52.6% at weeks 8 and 52, respectively. For 52 weeks, the overall incidence of ADRs and serious adverse drug reactions (SADRs) was 11.7% and 6.7%, respectively. The most frequently reported SADRs was worsening of CD (1.8%). In multivariate analysis, ADRs incidence was significantly lower in patients with ileal involvement of CD (odds ratio = 0.25, 95% CI 0.07-0.85, P = .026), although disease location has no association with effectiveness of UST. Conclusions: The present study identified no new safety concerns and effectiveness for CD in Japanese patients treated with UST.

8.
Sci Technol Adv Mater ; 23(1): 322-331, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35557510

RESUMO

The band structures and band gap energies, E g, of passive films formed on titanium (Ti) in simulated bioliquids, Hanks' solution (Hanks) and saline, were evaluated. Ti was polarized at 0, -0.1, and -0.2 VAg/AgCl, E f, for 1 h. After polarization, the surfaces were characterized using X-ray photoelectron spectroscopy, and the photoelectrochemical responses were evaluated. The current change during photoirradiation was recorded as a photocurrent transient at each measuring potential, E m, and by changing the wavelength of the incident light. Passive films consisted of a very thin TiO2 layer containing small amounts of Ti2O3 and TiO, hydroxyl groups, and water. During polarization in Hanks, calcium and phosphate ions were incorporated or formed calcium phosphate but not in saline. Calcium phosphate and hydroxyl groups influenced the band structure. E g was graded in Hanks but constant in saline, independent of E f and E m. The passive film on Ti behaved as an n-type semiconductor containing two layers: an inner oxide layer with a large E g and an outer hydroxide layer with a small E g. In Hanks, E g was 3.3-3.4 eV in the inner oxide layer and 2.9 eV in the outer hydroxide layer. In saline, E g was 3.3 eV in the inner layer and 2.7 eV in the outer layer. Calcium phosphate and hydroxyl groups influenced the band structure of the passive film. The E g of the outermost surface was smaller than that of TiO2 ceramics, which is probably one of the principles of the excellent biocompatibility of Ti among metals.

9.
Intest Res ; 20(3): 329-341, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34333910

RESUMO

BACKGROUND/AIMS: Golimumab (GLM) is an anti-tumor necrosis factor-α drug approved for treating moderate-to-severe active ulcerative colitis (UC). A 52-week post-marketing surveillance (PMS) was initiated to evaluate its safety and effectiveness in patients with UC in Japan. We present an interim report of the ongoing PMS. METHODS: Patients received 200 mg of subcutaneous GLM at week 0, 100 mg at week 2, and 100 mg 4 weekly thereafter. The safety analysis set included 392 patients with UC, and the effectiveness analysis set 387 patients. Safety and effectiveness were assessed at week 6. RESULTS: Adverse drug reactions (ADRs) were reported in 8.2% (32/392) and serious ADRs in 4.6% (18/392). The most frequent ADRs were infection and infestation (3.3%), with herpes zoster being the most common. ADRs were significantly higher in patients with concomitant corticosteroid use (odds ratio [OR], 3.45; 95% confidence interval [CI], 1.40-9.68). No significant difference in ADR incidence was observed between patients aged ≥65 and <65 years (OR, 1.23; 95% CI, 0.35-3.47). Six-week effectiveness of GLM was confirmed by a decrease in the partial Mayo score (-2.3; 95% CI, -2.6 to -2.1) and C-reactive protein levels (-0.64; 95% CI, -0.92 to -0.36), including in the biologics-experienced population. CONCLUSIONS: The safety and effectiveness of GLM at week 6 in a real-world setting were demonstrated in patients with UC in Japan. ADR patterns were consistent with previous reports with no new safety signals. Concomitant corticosteroid use may be associated with increased ADR incidence. The final results of the ongoing PMS are necessary for further evaluation.

10.
J Gastroenterol Hepatol ; 36(11): 3069-3076, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34180096

RESUMO

BACKGROUND AND AIM: Ustekinumab, a human anti-interleukin-12/23 monoclonal antibody, has been approved in Japan for the treatment of Crohn's disease. Here, we report the findings from an 8-week interim analysis of post-marketing surveillance to evaluate the safety and effectiveness of ustekinumab in Japanese patients with Crohn's disease. METHODS: Patients initiating ustekinumab treatment were prospectively evaluated from May 2017 to June 2020 at 91 medical centers in Japan. Adverse drug reactions (ADRs) and serious ADRs (SADRs) were monitored. Effectiveness was evaluated by clinical response, clinical remission, and changes in Crohn's Disease Activity Index (CDAI) and C-reactive protein (CRP) from baseline to week 8. Presence of perianal disease was documented at baseline and week 8. RESULTS: In total, 341 patients were enrolled in the study, of which 339 were included in the safety analysis while 334 were included in the effectiveness analysis. The overall incidences of ADRs and SADRs were 5.3% and 2.1%, respectively. Worsening of Crohn's disease was the most common event. The clinical response and clinical remission rate at week 8 were 40.0% and 48.5%, respectively. Significant improvements in CDAI and serum CRP (P < 0.001) were observed at week 8. CDAI decreased significantly (mean difference: -31.4; 95% confidence interval: -61.1, -1.7; P = 0.038) in biologics-naïve patients versus patients who had received two or more biologics. CONCLUSIONS: This 8-week interim analysis of the real-world study confirmed the effectiveness of ustekinumab-based therapy in Japanese patients with Crohn's disease. No new safety concerns were found during 8-week induction period in the Japanese clinical settings.


Assuntos
Produtos Biológicos , Doença de Crohn , Ustekinumab , Adulto , Produtos Biológicos/efeitos adversos , Produtos Biológicos/uso terapêutico , Doença de Crohn/tratamento farmacológico , Doença de Crohn/epidemiologia , Feminino , Humanos , Japão/epidemiologia , Masculino , Pessoa de Meia-Idade , Vigilância de Produtos Comercializados , Indução de Remissão , Resultado do Tratamento , Ustekinumab/efeitos adversos , Ustekinumab/uso terapêutico , Adulto Jovem
11.
Nanoscale ; 12(15): 8119-8132, 2020 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-32236272

RESUMO

Anodic TiO2 nanotubes that are grown on Ti substrates by a simple anodization in various types of fluoride containing electrolytes have attracted scientific and technological interest due to their wide potential applications, and therefore, numerous research efforts have been dedicated to these self-ordered oxide structures in the past decade. The present mini-review highlights less known but important aspects, such as the formation of spaced nanotubes with adjustable interspacing that is achieved in a few specific organic electrolytes, and strong effects of the metallic Ti substrate which significantly affect the growth of the tubes. We discuss the formation of oxide nanotubes grown from adequately alloyed substrates and noble metal nanoparticle decoration of tubes. We describe how specific heat-treatment can introduce a nanotwinned boundary in the oxide tube walls of single-walled nanotubes obtained by a decoring process. All the facts and findings were studied in recent years and TiO2 nanotubes can be upgraded with more optimized functionalities for their applications.

12.
ACS Appl Mater Interfaces ; 10(21): 18220-18226, 2018 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-29741090

RESUMO

Au and Pt do not form homogeneous bulk alloys as they are thermodynamically not miscible. However, we show that anodic TiO2 nanotubes (NTs) can in situ be uniformly decorated with homogeneous AuPt alloy nanoparticles (NPs) during their anodic growth. For this, a metallic Ti substrate containing low amounts of dissolved Au (0.1 atom %) and Pt (0.1 atom %) is used for anodizing. The matrix metal (Ti) is converted to oxide, whereas at the oxide/metal interface direct noble metal particle formation and alloying of Au and Pt takes place; continuously these particles are then picked up by the growing nanotube wall. In our experiments, the AuPt alloy NPs have an average size of 4.2 nm, and at the end of the anodic process, these are regularly dispersed over the TiO2 nanotubes. These alloyed AuPt particles act as excellent co-catalyst in photocatalytic H2 generation, with a H2 production rate of 12.04 µL h-1 under solar light. This represents a strongly enhanced activity as compared to TiO2 NTs decorated with monometallic particles of Au (7 µL h-1) or Pt (9.96 µL h-1).

13.
Angew Chem Int Ed Engl ; 55(11): 3763-7, 2016 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-26879340

RESUMO

Low-dose nitrogen implantation induces an ion and damage profile in TiO2 nanotubes that leads to "co-catalytic" activity for photocatalytic H2 -evolution (without the use of any noble metal). Ion implantation with adequate parameters creates this active zone limited to the top part of the tubes. The coupling of this top layer and the underlying non-implanted part of the nanotubes additionally contributes to an efficient carrier separation and thus to a significantly enhanced H2 generation.

14.
J Mech Behav Biomed Mater ; 56: 6-13, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26651063

RESUMO

The present study reports the corrosion fatigue of the Ti-6Al-4V alloy using cyclic deformation test in a simulated body fluid under cell culturing for the first time. Cyclic deformation tests were carried out using three types of specimens to reveal the effects of proteins and cells on the corrosion fatigue of the alloy. For the 1-day-immersed and 1-week-immersed specimens, tensile specimens were soaked in a simulated body fluid for 1 day and 1 week, respectively, before cyclic deformation test, whereas for the cell-cultured specimen, MC3T3-E1 osteoblast-like cells were seeded and then cultured on tensile specimens for 1 week. The incubation period for crack initiation was longer for the cell-cultured and 1-week-immersed specimens compared to that for the 1-day-immersed specimen. On the other hand, crack propagation period for the cell-cultured and 1-week-immersed specimens was shorter than that for the 1-day-immersed specimen. These results indicate that proteins and cells adhered on the alloy surface inhibit metal dissolution at newly created surface emerged by cyclic deformation to suppress crack initiation, whereas they accelerate crack propagation because dissolution at crack tip is accelerated in the occluded space formed under proteins and cells.


Assuntos
Materiais Biocompatíveis/química , Materiais Biomiméticos , Teste de Materiais , Titânio/química , Células 3T3 , Ligas , Animais , Corrosão , Eletroquímica , Camundongos , Osteoblastos/citologia , Propriedades de Superfície , Suporte de Carga
15.
Chem Commun (Camb) ; 50(53): 7067-70, 2014 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-24848598

RESUMO

Aligned CoF2 nanochannel layers have been formed by self-ordering electrochemical anodization. In voltammograms these layers provide multiple oxidation states, an almost ideal rectangular pseudocapacitive behavior, a high specific capacitance and good capacitance retention. These layers may thus be promising for supercapacitor applications.

16.
Oper Dent ; 35(1): 77-83, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20166414

RESUMO

This study examined the relationship between the adhesive application time and enamel bond strength of several single-step self-etch adhesive systems. The adhesives used were: Bond Force (BF, Tokuyama Dental Corporation, Tokyo, Japan), Clearfil tri-S Bond (CT, Kuraray Medical Inc, Tokyo, Japan), iBond Self-Etch (IB, Heraeus Kulzer, Armonk, NY) and OptiBond All-in-One (OB, sds Kerr). Bovine mandibular incisors were mounted in self-curing resin and wet ground with #600-grit silicon carbide paper to expose labial enamel. Adhesives were applied for 10, 20 or 40 seconds and the resin composites were condensed into a mold (phi4 x 2 mm) on the enamel and light irradiated. Ten samples per test group were stored in 37 degrees C water for 24 hours, then shear tested at a crosshead speed of 1.0 mm/minute. One-way ANOVA and the Tukey HSD test (alpha = 0.05) were performed within each adhesive system. The enamel surfaces after adhesive application were also observed in a Field Emission Electron Probe Surface Roughness Analyzer and the Ra value was calculated. The enamel bond strength ranged from 13.6 to 17.8 MPa for BF, 13.6 to 15.9 MPa for CT, 14.3 to 16.2 MPa for IB and 13.4 to 19.8 MPa for OB. Significant increases in bond strength were found for the 40-second application groups, except for IB. No changes in Ra value were found for BF and IB, while significant decreases in Ra value were recorded with 40-second application for CT and OB. The data suggested that the duration of the single-step self-etch adhesive application was a crucial factor for determining the enamel bond strengths of some of the single-step self-etch adhesives employed in the current study.


Assuntos
Colagem Dentária/métodos , Esmalte Dentário/ultraestrutura , Cimentos de Resina/química , Condicionamento Ácido do Dente , Animais , Compostos Inorgânicos de Carbono/química , Bovinos , Resinas Compostas/química , Teste de Materiais , Microscopia Eletrônica de Varredura , Polietilenoglicóis/química , Ácidos Polimetacrílicos/química , Resistência ao Cisalhamento , Compostos de Silício/química , Estresse Mecânico , Propriedades de Superfície , Temperatura , Fatores de Tempo , Água/química
17.
Chem Commun (Camb) ; (15): 2008-10, 2009 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-19333473

RESUMO

Self-organized TiO(2)-MoO(3) composite oxide nano-tubes with tunable dimensions are successfully fabricated by anodization of a Ti-Mo alloy and these nano-tube layers exhibit a significantly enhanced electrochromic color contrast compared with plain TiO(2) nano-tubes.

18.
Dent Mater J ; 27(5): 654-9, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18972780

RESUMO

The influence of temperature and relative humidity (RH) on the bond strength of orthodontic adhesives was investigated. Two self-etching/composite type, one acid-etching/composite type, and one acid-etching/PMMA type of adhesives were examined under different temperature and RH conditions. Orthodontic brackets were bonded to bovine enamel, and shear bond strength test was performed at a crosshead speed of 1.0 mm/min after 24-hour storage in 37 degrees C water. Data were analyzed by Tukey's HSD test. Each specimen was assigned an ARI score. All the materials tested exhibited their highest bond strength under room conditions at a range of 10.4-17.0 MPa. Conversely, when under a lower RH condition, bond strength for all the systems ranked the lowest within a range of 6.8-12.0 MPa, with bond failure at the bracket-adhesive interface. These results demonstrated that care should be exercised when using orthodontic adhesive systems in the oral environment.


Assuntos
Condicionamento Ácido do Dente/métodos , Cura Luminosa de Adesivos Dentários , Braquetes Ortodônticos , Cimentos de Resina/química , Resinas Acrílicas/química , Animais , Bovinos , Falha de Equipamento , Umidade , Teste de Materiais , Metacrilatos/química , Ácidos Fosfóricos/química , Resistência ao Cisalhamento , Estresse Mecânico , Propriedades de Superfície , Temperatura , Fatores de Tempo , Água/química
19.
J Oral Sci ; 49(3): 183-9, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17928723

RESUMO

The purpose of this study was to examine the microtensile bond strength of a single-step self-etch adhesive system (Clearfil tri-S Bond and One-Up Bond F Plus) to bovine dentin. Adhesive was applied to a flat dentin surface, and resin composite was bonded according to the manufacturers' instructions. After 24 h storage in distilled water at 37 degrees C, hourglass-shaped specimens were produced. These were subjected to microtensile bond strength testing at a cross-head speed of 1.0 mm/min. The results were analyzed using Student's t-test at a significance level of 0.05. Field-emission scanning electron microscopy (FE-SEM) observations of the fractured specimens and the adhesive-treated dentin surfaces were also conducted. The bond strength of Clearfil tri-S Bond was not significantly different from that of One-Up Bond F Plus, 41.1 +/- 10.1 versus 42.3 +/- 6.0 MPa. Mode of failure analysis for Clearfil tri-S Bond revealed an equal distribution between the three types of failure, and the predominant mode of failure was adhesive for One-Up Bond F Plus. FE-SEM observations of dentin to which adhesive had been applied revealed that the smear layer had been removed and the collagen fibers exposed.


Assuntos
Condicionamento Ácido do Dente/métodos , Colagem Dentária , Análise do Estresse Dentário , Adesivos Dentinários , Dentina , Cimentos de Resina , Animais , Bovinos , Permeabilidade da Dentina , Metacrilatos , Microscopia Eletrônica de Varredura/métodos , Camada de Esfregaço , Resistência à Tração
20.
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