• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 260
  • 65
  • 20
  • 12
  • 12
  • 12
  • 12
  • 11
  • 10
  • 2
  • 2
  • 2
  • 2
  • 2
  • 1
  • Tagged with
  • 369
  • 369
  • 259
  • 242
  • 199
  • 69
  • 57
  • 55
  • 51
  • 47
  • 45
  • 41
  • 40
  • 38
  • 36
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
141

Avaliação comparativa de resinas compostas fluidas em relação a resistência à abrasão (escovação simulada). / Abrasion resistance of flowable resin composites by comparative analysis of simulated toothbrushing.

Garcia, Fernanda Cristina Pimentel 02 March 2001 (has links)
O presente estudo procurou analisar, através de um teste de abrasão in vitro por escovação simulada, a perda de massa e a alteração da rugosidade superficial em resinas compostas "fluidas" e resinas compostas controles. As marcas comerciais utilizadas foram: Aeliteflo-Bisco (A), Natural Flow-DFL (N), Wave-SDI (W), Flow-It Lf-Jeneric/Pentron (FLf) e Flow-It-Jeneric/Pentron (F). Uma resina composta de partículas híbridas Z100-3M (Z) e uma de micropartículas Silux Plus-3M (S) foram utilizadas como controle. Foram confeccionados 84 corpos-de-prova, de 5mm de diâmetro e 3mm de espessura, sendo 12 para cada marca comercial utilizada. Para o acabamento e o polimento dos corpos-de-prova foram utilizados discos Sof-Lex (3M) nas granulações fina (cor azul média) e superfina (cor azul claro), por tempo médio de 15/20 segundos, para cada granulação, em baixa velocidade. Para os ensaios de abrasão, foi utilizada uma máquina apropriada associada à escova Colgate Classic Infantil (Colgate-Palmolive) de cerdas macias e solução do creme dental, Colgate Proteção Anticáries com MFP (Colgate-Palmolive), diluído em água deionizada na proporção de 1:2. No teste in vitro, foram realizados aproximadamente100.000 ciclos. A determinação do desgaste dos materiais foi verificada pela quantidade de massa perdida após os ensaios, com a utilização de uma balança analítica Sartorius. A rugosidade foi determinada quantitativamente na superfície dos corpos-de-prova, com o auxílio de um rugosímetro Hommel Tester T 1000, comparando a diferença obtida após os testes de escovação e, qualitativamente, por microscopia eletrônica de varredura. Os resultados foram analisados pela variância a um critério ANOVA e pelo Teste de Tukey com p<0,05. Pelo coeficiente de Pearson não foi verificada correlação (r=-0,0296) entre porcentagem de perda de massa e rugosidade de superfície. Os materiais não apresentaram diferenças estatisticamente significantes quanto à alteração de massa, somente quanto à rugosidade superficial. A resina A apresentou a maior alteração de massa, (3,77%), seguida da resina de micropartículas S (3,04%). Em contrapartida, a resina híbrida convencional Z apresentou a menor alteração de massa (1,29%), ficando o restante das resinas "fluidas" com alteração intermediária a estas três resinas. A maior alteração de rugosidade foi verificada para a resina W (1,1720mm), com diferenças estatisticamente significantes em relação às outras resinas testadas: S (0,2749mm), Z (0,2495mm), FLf (0,1597mm), F (0,1217mm), N (0,0620mm) e A (0,0505mm). / This research aimed to assess the wear of flowable resin composites through an in vitro simulated toothbrushing abrasion test. The weight loss and surface roughness analysis were performed using five commercial brands: Aeliteflo, Flow-It, Flow-It Lf, Natural Flow and Wave. Hybrid Z-100 and Microfilled Silux Plus composites have been included as controls. Twelve samples (discs) of each material were prepared with 5mm thickness and 3mm in diameter. The test was performed up to 100.000 cicles with an appropriate machine containing soft bristles tips, dentifrice solution and deionized water in order to simulate toothbrushing. The weight loss was determined by the differences between the initial and final weights ( before and after toothbrushing) using a Sartorius analytical scale. After 5 readings, in a T 1000 Hommel testing machine, the evaluation of surface roughness was obtained by the differences between initial and final means. The analyzed ( ANOVA and Tukey, p< 0,05) results showed that Silux Plus, Flow-it, Wave, Flow-It Lf and Natural Flow had an intermediate weight loss (3,04; 2,70; 2,19; 2,12 and 2,04% respectively). Z-100 exhibited the lowest (1,29%) weight loss, whereas Aeliteflo, the highest (3,77%). Wave showed the highest surface roughness variation (1,1720mm), statistically different from the other groups, which exhibited the following differences: Silux Plus (0,2749mm), Z-100 (0,2495mm), Flow-it Lf (0,1597mm), Flow-It (0,1217mm), Natural Flow (0,0620mm) and Aeliteflo (0,0506mm). Aeliteflo presented the highest weight loss and the lowest surface roughness difference; on the other hand, Wave showed the highest surface roughness difference and an intermediate weight loss when compared with the other tested resins.
142

Influência da aplicação de um sistema adesivo na resistência de união entre resinas bulk fill flow e resina nanoparticulada em reparos /

Castro, Maria José Domingues de. January 2018 (has links)
Orientador: Rebeca Di Nicoló / Coorientadora: Fernanda Alves Feitosa / Banca: Eduardo Bresciani / Banca: Eduardo Galera da Silva / Banca: Levy Anderson Cesar Alves / Banca: Fabio Matuda / Resumo: O objetivo desta pesquisa foi avaliar a influência da utilização ou não do bond do sistema adesivo Adper Scotchbond Multiuso(A) e o bond Gluma da Heraeus(G) na resistência de união entre as resinas do tipo flow Filtek Bulk Fill Flow(F) e X-tra base (X) como base e uma convencional nanoparticulada Z350 XT(Z)) como cobertura. Simulando assim seu uso em reparos de restaurações diretas em dentes posteriores. Foram confeccionados 120 espécimes em resina composta do tipo flow no formato tronco-cônico com as dimensões de 2mm base menor, 4mm de altura e 4 mm de base maior. 60 Filtek Bulk Fill(F) e 60 X-tra base (X). Metade de cada grupo (n=30) foi envelhecida por termociclagem 5.000 ciclos de 5°C a 55°C, (FE, XE), a outra metade não sofreu envelhecimento (FN e XN). Esses espécimes foram divididos em 3 subgrupos (n=10), sobre a base menor dessas 10 amostras foi aplicado o Bond de cada sistema adesivo após condicionadas pelos seus respectivos ácidos nos tempos preconizados pelos fabricantes. As outras 10 unidades de cada grupo não receberam qualquer sistema adesivo. Na simulação do reparo as duas primeiras metades em teflon foram invertidas ficando a área menor voltada pra cima. Sobre essa face foram colocadas outras duas metades em teflon com a área menor voltada para baixo. Foi inserida então a resina Z350 pela técnica incremental e fotopolimerizada por 20s a 800mw/cm². Após 24h de armazenamento em água destilada, em estufa bacteriológica os espécimes, agora com formato de ampulheta,... (Resumo completo, clicar acesso eletrônico abaixo) / The aim of our paper was to analyse the bonding influence of Adper Scotchbond Multipurpose Adhesive (A) and Heraeus Gluma universal bond (G), or no bond application, on bond strength between microhibrid Filtek Bulk Fill Flow (F) and nanohibrid X-tra base (X) as based composite resin and the conventional nanoparticulate Z350 XT (Z)) as cover. Simulating non-invasive repairs of direct restorations on posterior teeth. A total of 120 specimens were made from flow composite resin in the conical trunk format with the dimensions of 2x4x4, for 40s with Led-5 (N/S LD51803005) at 800mw/cm². Sixty Filtek bulk fill (F) and sixty X-tra base (X) were made. Half of each group (n=30) was aged by thermocycling 5,000 cycles from 5° C to 55° C, (FE, XE), the other half were not subjected to any aging procedure (FN, XN). These specimens were randomly divided into 3 subgroups (n = 10), on the smaller diameter of the 10 samples the Bond of each adhesive system were applied after conditioned by their respectively acids at the time recommended by the manufacturers. The other 10 units of each group did not receive any adhesive system. In the sequency of repair simulation the first two Teflon halves were turned up with the smaller diameter turned upwards. Above this face were placed two other halves in Teflon with the smaller diameter facing down. The Z350 repair composite resin were inserted by incremental technique and photopolymerized for 20s at 800mw/cm². After 24h of storage in distilled water in a bacteriological oven, the now hourglass-shaped specimens were drawn in the universal testing machine EMIC. All the fractured specimens had the type of failure analyzed in stereomicroscope. The most significant faulting specimens were evaluated with electronic microscope (MEV). The data collected at the traction test were analyzed through 3-factor ANOVA and Tukey's test (p <5%). There was... (Complete abstract click electronic access below) / Doutor
143

Flexural strength comparison of monolayer resin composite to bilayer resin/liner composite

Azzam, Mai Ahmed. January 2009 (has links)
Thesis (M.S.D.)--Indiana University School of Dentistry, 2009. / Title from PDF t. p. (viewed Feb. 5, 2010) Advisor(s): Jeffrey A. Platt, Chair of the Research Committee, Joseph Legan, Carl J. Andres, David Brown, Burak Taskonak . Curriculum vitae. Includes abstract. Includes bibliographical references (leaves 45-52).
144

A comparison of bond strength between an orthodontic adhesive resin cured with halogen light or plasma arc light an in vitro and in vivo study /

Signorelli, Michael D. January 2003 (has links)
Thesis (M.S.)--West Virginia University, 2003. / Title from document title page. Document formatted into pages; contains viii, 107 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 66-71).
145

In vitro compressive fracture resistance of the human maxillary first premolar with different mod cavity design and restorative materials

Wu, Wen-Chou. January 2007 (has links) (PDF)
Thesis (M.S.)--University of Alabama at Birmingham, 2007. / Title from first page of PDF file (viewed Feb. 6, 2008). Includes bibliographical references (p. 36-42).
146

Calcium aluminate cement as dental restorative : mechanical properties and clinical durability /

Sunnegårdh-Grönberg, Karin, January 2004 (has links)
Diss. (sammanfattning) Umeå : Univ., 2004. / Härtill 5 uppsatser.
147

Penetration of unfilled and composite resins into acid-etched human enamel a thesis submitted in partial fulfillment ... restorative dentistry ... /

Pahlavan, Ayoub. January 1975 (has links)
Thesis (M.S.)--University of Michigan, 1975.
148

Potential iatrogenic effects on enamel treated with a light cured flouride releasing filled resin

Griggs, Henry G. January 2008 (has links) (PDF)
Thesis (M.S.)--University of Alabama at Birmingham, 2008. / Title from first page of PDF file (viewed May 30, 2008). Includes bibliographical references.
149

The effect of inhibitor and initiator concentration on degree of conversion, flexural strength and polymerization shrinkage

Shaabin, Maram, January 2009 (has links)
Thesis (M.A.)--Indiana University School of Dentistry, 2009. / Title from PDF t. p. (viewed Mar. 30, 2010) Advisor(s): Gabriel Tien-Min Chu, Chair of the Research Committee, Melvin R. Lund, Bruce A. Matis, Carlos Gonzalez-Cabezas, Michael A. Cochran. Curriculum vitae. Includes abstract. Includes bibliographical references (leaves 79-87).
150

Penetration of unfilled and composite resins into acid-etched human enamel a thesis submitted in partial fulfillment ... restorative dentistry ... /

Pahlavan, Ayoub. January 1975 (has links)
Thesis (M.S.)--University of Michigan, 1975.

Page generated in 0.0571 seconds