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1.
Gen Dent ; 62(1): e22-7, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24401360

RESUMO

The aim of this study was to evaluate the effect of novel surface treatments of Y-TZP ceramics on initial shear bond strengths to resin cement. Eighty-four samples (7 x 6 x 5 mm) were randomly divided into 6 groups (n=14): Group1 (G1), no treatment; Group 2 (G2), air-borne particle abrasion with silica-coated aluminum oxide particles; Group 3 (G3), vitreous application 1 + etching with hydrofluoric acid; Group 4 (G4), vitreous application 1 + tribosilicatization; Group 5 (G5), vitreous application 2 + etching; Group 6 (G6), vitreous application 2 + tribosilicatization. Surface roughness (Ra) evaluation was performed by optical profilometry, scanning electron microscopy, and X-ray spectroscopy. The samples were silanized, and resin cement cylinders (3 x 2 mm) were built on the treated surfaces, light-cured and submitted to shear testing (1 mm/min). The failure mode was evaluated by SEM. Bond strength data were statistically analyzed using 1-way ANOVA and Tukey's test (α=0.05). Bond strength results were significantly affected by surface treatments (P = 0.0001). G5 and G3 presented increased Ra parameters and showed highest bond strength results (17.8 ± 5.5 and 13.3 ± 4.1, respectively). Failure modes were mainly mixed in all groups except for G1. The results confirmed that the approach of coating surface-conditioned Y-TZP with a vitreous material increased the initial shear bond strength to resin cement.


Assuntos
Colagem Dentária/métodos , Preparo Prostodôntico do Dente/métodos , Ítrio/uso terapêutico , Zircônio/uso terapêutico , Condicionamento Ácido do Dente/métodos , Cimentos Dentários/uso terapêutico , Análise do Estresse Dentário , Humanos , Microscopia Eletrônica de Varredura , Cimentos de Resina/uso terapêutico , Espectrometria por Raios X , Ítrio/administração & dosagem , Zircônio/administração & dosagem
2.
Acta Odontol Latinoam ; 25(3): 255-60, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23798071

RESUMO

The aim of this study was to evaluate the hardness, roughness and mass loss of an acrylic denture base resin after in vitro exposure to four disinfectant solutions. Forty specimens (Clássico, Brazil) were prepared and randomly assigned to 4 groups n = 10) according to the disinfectant solution: G1: control, stored in distilled water at 37 degrees C; G2: 1% sodium hypochlorite; G3: 2% glutaraldehyde; G4: 4% chlorhexidine. G2 to G4 were immersed for 60 minutes in the disinfectant solution. Measurements were carried out both before and after immersion in the solution. The surface was analyzed with a surface roughness tester (Surfcorder SE 1700 KOZAKALAB), a microdurometer FM-700 (Future Tech) and a scanning electron microscope (DSM 962-ZEISS). Loss of mass was determined with a digital weighing scale. After disinfection procedures, values were analyzed statistically. The acrylic denture base resin may be vulnerable to surface changes after in vitro immersion in the disinfectant solutions studied.


Assuntos
Resinas Acrílicas , Bases de Dentadura , Desinfetantes/farmacologia , Esterilização , Soluções
3.
Acta odontol. latinoam ; 23(3): 249-256, Dec. 2010. tab
Artigo em Inglês | LILACS | ID: biblio-949671

RESUMO

The aim of this study was to assess the effect of bleaching agents (10% and 16% carbamide peroxide) on the roughness of two dental ceramics in vitro, and to analyze the surface by scanning electronic microscopy (SEM). Two bleaching agents (10% and 16% / Whiteness, FGM Gel) and two microparticle feldspathic ceramics (Vita VM7 and Vita VM13) were used. Forty disks of Vita VM7 and Vita VM13 ceramic were manufactured, measuring 4mm in diameter and 4mm high, in accordance with the manufacturers’ recommendations, and were divided into 4 groups (n=10): (1) VM7 + Whiteness 10%; (2) VM7 + Whiteness 16%; (3) VM13 + Whiteness 10%; (4) VM13 + Whiteness 16%. The bleaching agent was applied for 8 hours a day for 15 days and during the intervals the test specimens were stored in distilled water at 37°C. The roughness (Ra) of the test specimens was evaluated before and after exposure to the bleaching agents using a laser roughness meter and the topographic description was analyzed by SEM. The statistical analysis of roughness data showed significant differences in the VM7 groups, using paired t-test, p=0.05 (VM7 + Whiteness 10%: p=0.002; VM7 + Whiteness 16%: p=0.001) and two-sample t-test (VM7 p=0,047), and no significant difference was found among VM13 groups. The qualitative SEM analysis showed different degrees of surface changes. The results suggest that the roughness of the tested ceramic surfaces increased after exposure to the bleaching agents.


O objetivo do estudo foi avaliar o efeito de agente clareador (10% e 16% de peroxido de carbamida) na rugosidade de duas ceramicas dentais in vitro e analisar a superficie atraves da microscopia eletronica de varredura (SEM). Foram utilizados dois agentes clareadores (10% e 16% / Whiteness, FGM Gel) e duas ceramicas feldspaticas microparticuladas (Vita VM7 e Vita VM13). Foram confeccionados quarenta discos de ceramica Vita VM7 e Vita VM13, com 4mm de diametro e 4mm de altura, de acordo com as recomendacoes do fabricante, sendo divididos em 4 grupos (n=10): G1- VM7 + Whiteness 10%, G2- VM7 + Whiteness 16%, G3- VM13 + Whiteness 10% e G4- VM13 + Whiteness 16%. O agente clareador foi aplicado por 8 horas durante 15 dias e durante os intervalos os corpos de prova (cp) ficavam armazenados em agua destilada a 37°C. A rugosidade (Ra) dos cp foi avaliada antes e apos a exposicao aos agentes clareadores utilizando o rugosimetro a laser Perthomether S8P, e a descricao topografica foi analisada no MEV. A analise estatistica na rugosidade mostrou diferenca significante entre os grupos da VM7, usando o teste pareado, p=0.05 (VM7 + Whiteness 10%: p=0.002; VM7 + Whiteness 16%: p=0.001) e nao foi encontrado diferenca estatistica para os grupos da VM13. A descricao qualitativa no SEM evidenciou alteracao nas superficies em diferentes graus. Os resultados sugeriram que as superficies das ceramicas testadas aumentaram a rugosidade apos a exposicao ao agente clareador.


Assuntos
Humanos , Peróxidos/química , Ureia/análogos & derivados , Porcelana Dentária/química , Clareadores Dentários/química , Peróxidos/administração & dosagem , Propriedades de Superfície , Temperatura , Fatores de Tempo , Ureia/administração & dosagem , Ureia/química , Teste de Materiais , Água/química , Microscopia Eletrônica de Varredura , Cerâmica/química , Compostos de Potássio/química , Silicatos de Alumínio/química , Clareadores Dentários/administração & dosagem , Peróxido de Carbamida , Géis , Lasers
4.
Acta Odontol Latinoam ; 23(2): 79-83, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-21053678

RESUMO

This study examined the effect of 10% and 16% carbamide peroxide bleaching agents on the surface microhardness of micro-particulate feldspathic ceramics (VM7 and VM13, Vita Zahnfabrik). Forty specimens (8-mm diameter, 2-mm thickness) were divided into four groups (n=10): GI-VM7 + 10% Whiteness, G2-VM7 + 16% Whiteness, G3-VM13 + 10% and G4-VM13 + 16% Whiteness. The home-use bleaching agents were applied for 8 hours on 15 days, and the specimens were stored in distilled water at 37 degrees C. The Vickers hardness number (HV) was determined for each specimen. Data were analyzed by the Wilcoxon and Mann-Whitney tests (p < 0.05). The microhardness values before exposure were: g1-433 (57); g2-486 (22); g3-509 (28); g4-518 (24), and after exposure: G1-349 (32); G2-496 (95); G3-519 (38); G4-502 (81). G2 exhibited a higher and significant difference than GI in VM7 groups, and the effect of bleaching concentration was shown to be significant by the Mann-Whitney test. And for VM13, both the Wilcoxon and Mann-Whitney tests showed no significant differences. When using 10% carbamide peroxide, the microhardness of VM7 ceramic was affected, and there were no effect on the microhardness between VM7 and VM13 ceramics when 16% carbamide peroxide was used.


Assuntos
Cerâmica , Materiais Dentários , Dureza/efeitos dos fármacos , Peróxidos/farmacologia , Clareadores Dentários/farmacologia , Ureia/análogos & derivados , Peróxido de Carbamida , Testes de Dureza , Ureia/farmacologia
5.
Acta odontol. latinoam ; 23(2): 79-83, Sept. 2010. tab
Artigo em Inglês | LILACS | ID: biblio-949642

RESUMO

This study examined the effect of 10% and 16% carbamide peroxide bleaching agents on the surface microhardness of micro-particulate feldspathic ceramics (VM7 and VM13, Vita Zahnfabrik). Forty specimens (8-mm diameter, 2-mm thickness) were divided into four groups (n=10): G1- VM7 + 10% Whiteness, G2- VM7 + 16% Whiteness, G3- VM13 + 10% and G4- VM13 + 16% Whiteness. The home-use bleaching agents were applied for 8 hours on 15 days, and the specimens were stored in distilled water at 37°C. The Vickers hardness number (HV) was determined for each specimen. Data were analyzed by the Wilcoxon and Mann- Whitney tests (p<0.05). The microhardness values before exposure were: g1- 433 (57); g2- 486 (22); g3- 509 (28); g4- 518 (24), and after exposure: G1- 349 (32); G2- 496 (95); G3- 519 (38); G4- 502 (81). G2 exhibited a higher and significant difference than G1 in VM7 groups, and the effect of bleaching concentration was shown to be significant by the Mann-Whitney test. And for VM13, both the Wilcoxon and Mann-Whitney tests showed no significant differences. When using 10% carbamide peroxide, the microhardness of VM7 ceramic was affected, and there were no effect on the microhardness between VM7 and VM13 ceramics when 16% carbamide peroxide was used.


Este estudo examinou o efeito do agente clareador peroxido de carbamida a 10% e a 16% na microdureza superficial de ceramicas feldspaticas micro-particuladas (VM7 e VM13, Vita Zahnfabrik). Quarenta corpos-de-prova (8 mm de diametro, 2 mm de espessura) foram divididos em quatro grupos (n=10): G1- VM7 + 10% Whiteness, G2- VM7 + 16% Whiteness, G3- VM13 + 10% e G4- VM13 + 16% Whiteness. Os agentes clareadores foram aplicados por 8 horas durante 15 dias e os cp foram armazenados em agua destilada a 37°C. A dureza Vickers (HV) de cada cp foi determinada. Os dados foram analisados pelos testes de Wilcoxon e Mann-Whitney (p<0.05). Os valores da dureza antes da exposicao ao agente clareador foram: g1- 433 (57); g2- 486 (22); g3- 509 (28); g4- 518 (24), e depois da exposicao: G1- 349 (32); G2- 496 (95); G3- 519 (38); G4- 502 (81). G2 exibiu diferenca significante e microdureza maior comparado ao G1 nos grupos da VM7 e o efeito da concentracao do clareador foi significante, apresentados atraves dos testes Mann-Whitney. Para VM13, ambos testes, Wilcoxon e Mann-Whitney, nao apresentaram diferenca significante. Quando o peroxido de carbamida a 10% foi avaliado, a microdureza da ceramica VM7 foi afetada, e nao houve diferenca na microdureza entre as ceramicas VM7 e VM13 quando o peroxido de carbamida a 16% foi utilizado.


Assuntos
Peróxidos/farmacologia , Ureia/análogos & derivados , Cerâmica , Materiais Dentários , Clareadores Dentários/farmacologia , Dureza/efeitos dos fármacos , Ureia/farmacologia , Peróxido de Carbamida , Testes de Dureza
6.
Acta Odontol Latinoam ; 23(3): 257-64, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-21638969

RESUMO

The aim of this study was to assess the effect of bleaching agents (10% and 16% carbamide peroxide) on the roughness of two dental ceramics in vitro, and to analyze the surface by scanning electronic microscopy (SEM). Two bleaching agents (10% and 16%/Whiteness, FGM Gel) and two microparticle feldspathic ceramics (Vita VM7 and Vita VM13) were used. Forty disks of Vita VM7 and Vita VM13 ceramic were manufactured, measuring 4 mm in diameter and 4 mm high, in accordance with the manufacturers' recommendations, and were divided into 4 groups (n = 10): (1) VM7 + Whiteness 10%; (2) VM7 + Whiteness 16%; (3) VM13 + Whiteness 10%; (4) VM13 + Whiteness 16%. The bleaching agent was applied for 8 hours a day for 15 days and during the intervals the test specimens were stored in distilled water at 37 degrees C. The roughness (Ra) of the test specimens was evaluated before and after exposure to the bleaching agents using a laser roughness meter and the topographic description was analyzed by SEM. The statistical analysis of roughness data showed significant differences in the VM7 groups, using paired t-test, p = 0.05 (VM7 + Whiteness 10%: p = 0.002; VM7 + Whiteness 16%: p = 0.001) and two-sample t-test (VM7 p = 0.047), and no significant difference was found among VM13 groups. The qualitative SEM analysis showed different degrees of surface changes. The results suggest that the roughness of the tested ceramic surfaces increased after exposure to the bleaching agents.


Assuntos
Porcelana Dentária/química , Peróxidos/química , Clareadores Dentários/química , Ureia/análogos & derivados , Silicatos de Alumínio/química , Peróxido de Carbamida , Cerâmica/química , Géis , Humanos , Lasers , Teste de Materiais , Microscopia Eletrônica de Varredura , Peróxidos/administração & dosagem , Compostos de Potássio/química , Propriedades de Superfície , Temperatura , Fatores de Tempo , Clareadores Dentários/administração & dosagem , Ureia/administração & dosagem , Ureia/química , Água/química
7.
Acta Odontol Latinoam ; 20(2): 97-102, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-18590258

RESUMO

The aim of this study was to evaluate the shear bond strength of Co-Cr and Ni-Cr metal alloys and a specific ceramic, submitted to different thermocycling immersion times. Sixty metal-ceramic specimens were confectioned and standardized in cylindricalformat. Three thermocycling conditions were evaluated: without thermocycling, 3,000 cycles (5 degrees C/55 degrees C+/-1) with 30s of immersion time and 3,000 cycles (5 degrees C/55 degrees C+/-1) with 60s. The shear bond strength was performed in a universal testing machine, using a special device to concentrate the tension at the metal/ceramic interface during the test. The load was applied until fracture of the specimens. The data was statistically analyzed by ANOVA (two-way) and Tukey (p<0.05) test. The results didn't show significant statistic differences between the metal-porcelain combinations. Nevertheless, both metal-ceramic systems submitted to 60s of immersion time showed lower values compared to specimens without thermocycling. It was concluded that the thermocycling immersion time of 1 minute affect the shear bond strength values for the Ni-Cr/porcelain and Cr-Co/porcelain systems.


Assuntos
Ligas de Cromo/química , Colagem Dentária , Porcelana Dentária/química , Ligas Metalo-Cerâmicas/química , Análise do Estresse Dentário/instrumentação , Humanos , Imersão , Teste de Materiais , Resistência ao Cisalhamento , Estresse Mecânico , Temperatura , Fatores de Tempo
8.
Acta odontol. latinoam ; 20(2): 97-102, 2007. ilus, tab, graf
Artigo em Inglês | LILACS | ID: lil-502099

RESUMO

El objetivo de este estudio fue evaluar la resistencia a cizallamiento de aleaciones metálicas de Co-Cr y Ni-Cr; con un mismo tipo de cerámica, sometidos a diferentes tiempos de inmersión en el termociclaje. Sesenta especímenes fueron confeccionados de forma standarden formato cilindrico. Tres condiciones de termociclaje fueron evaluadas: sin termociclaje, 3000 ciclos (5ºC/55ºC±1) con 30s y 3.000 ciclos (5ºC/55ºC±1) con 60s de tiempo de inmersión. El ensayo de cizallamiento fue realizado en una máquina universal usando un dispositivo para concentrar la tensión en la interfase metalocerámica durante el test. La carga fue aplicada hasta que ocurra la fractura de los especimenes. La información fue estadísticamente analizada por ANOVA(two-way) y el test de Tukey (p<0,05). Los resultados no mostraron diferencia estadísticamente significante entre las combinaciones metal-porcelana. Sin embargo, ambas combinaciones metalocerámicas sometidas a 60s de tiempo de inmersión mostraron valores más bajos en comparación con los especimenes del grupo sin termociclaje. Fue concluido que el tiempo de inmersión de termociclaje de 1 minuto afectó los valores de resistencia de cizallamiento en los grupos de Ni-Cr/porcelana y Cr-Co/porcelana.


Assuntos
Ligas de Cromo/química , Ligas Dentárias/química , Cerâmica/química , Colagem Dentária/métodos , Análise de Variância , Ligas Metalo-Cerâmicas/química , Cobalto/química , Falha de Restauração Dentária , Teste de Materiais , Níquel/química , Interpretação Estatística de Dados , Fraturas dos Dentes , Termodinâmica/métodos
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