Efeito do condicionamento de pinos de fibra de vidro na microdureza e morfologia superficial

• Ano de defesa: 2011
• Autor(a) principal: Gonçalves, Jorge Alberto
• Orientador(a): Mota, Eduardo Gonçalves
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Pontifícia Universidade Católica do Rio Grande do Sul; Porto Alegre
• Palavras-chave em Português: ODONTOLOGIA; MATERIAIS DENTÁRIOS; PINOS DENTÁRIOS; FIBRAS DE VIDRO
• Link de acesso: http://hdl.handle.net/10923/385

Article 1. The purpose of this study was to verify the influence of surface treatment with 10% and 24% hydrogen peroxide (H2O2) and acetone p. a. on the superficial microhardness in glass fiber posts in coronary, middle and apical thirds. The surface morphology of the posts treated with H2O2 and acetone p. a. , compared to the post without any surfaces treatment, was evaluated qualitatively, through scanning electron microscopy. Thirty six glass fiber post (Exacto, Ângelus, Londrina, PR, Brazil) were embedded on epoxy resin (EMBed 812, Polysciences, Inc. , Warrington, PA, USA) in cylinders of PVC (Ø = 20mm and h = 15mm) with its long axis parallel to the surface. After the resin polymerization, all specimens were abraded with sandpaper until expose the wider diameter of the post with silicon carbide sandpaper grit 400, 600, 1200, and 4000 and a felt disc in diamond suspension (1. 0 μm). The glass fiber posts were divided, randomly, into four groups (n = 9) as follows: group 1- post without surface treatment (control group), group 2 - post etched with 10% H2O2 for 1 min. , group 3 - post etched with 24% H2O2 for 1 min. and group 4 - post etched with acetone for 1min.After, all groups were tested for Vickers microhardness test in three different thirds of fiber post (coronary, middle and apical) with a load of 1 g per 5 s. Each specimen received three indentations (one on each third) in microdurometer (tester Shimadzu HMV, Shimadzu, Kyoto, Japan). The results were analyzed statistically using ANOVA with two fixed factors and Tukey's test at α = 0. 05, which showed control group a mean VHN of 1. 86 (± 0. 46), higher than group 2 (0. 72 ± 0. 18), group 3 (0. 57 ± 0. 09) and group 4 (0. 51 ± 0. 09). The control group had the highest average microhardness in the apical third superior to others interactions, which were similar among them. The images of SEM of specimen for differents groups showed the surface treatments tested alter the surface morphology, removing the epoxy matrix of fiber posts partially, exposing the glass fibers and indicating its partial erosion.Article 2. The purpose of this study was to verify the influence of surface treatment with 10% and 24% hydrogen peroxide (H2O2), 50μm aluminum oxide (Al2O3) and acetone p. a. on the superficial roughness (Ra) in glass fiber posts on coronary, middle and apical thirds. The surface morphology of the posts treated with H2O2 and acetone p. a. , compared to the post without any surfaces treatment, was evaluated qualitatively, through scanning electron microscopy (SEM). Fourty five glass fiber post (Exacto, Ângelus, Londrina, PR, Brazil) were embedded on epoxy resin (EMBed 812, Polysciences, Inc. , Warrington, PA, USA) in cylinders of PVC (Ø= 20 mm e h= 15mm), with its long axis parallel to the surface. After the resin polymerization, all specimen were abraded with sandpaper until expose the wider diameter of the post silicon carbide sandpaper grit 400, 600, 1200, and 4000 and felt disc in diamond suspension (1. 0 μm). Subsequently, the glass fiber posts were divided, randomly, into five groups (n= 9) as follows: group 1- post without surface treatment (control group), group 2 - post etched with 10% H2O2 for 1 min. , group 3 - post etched with 24% H2O2 for 1 min. , group 4 - post etched with Al2O3 (50μm) and group 5 – post etched with acetone p. a. for 1min. The surface of all specimens was evaluated in rugosimeter SJ–201 (Mitutoyo surftest analyser, Kanagawa, Japan), from three readings in each of one the three regions post (coronary, middle and apical thirds). The results were analyzed statistically using ANOVA test with two fixed factors and Tukey's test at α = 0. 05, by the SPSS computer program, which showed that group 5 presented an average of superficial roughness (Ra, SD) 0. 59 (± 0. 05), higher than control group (0. 15 ± 0. 05), group 2 (0. 18 ± 0. 05), group 3 (0. 20 ± 0. 03) and group 5 (0. 26 ± 0. 04).There was not difference in superficial roughness among the coronary, middle and apical regions of the fiber posts. The images of SEM of specimens for differents groups showed the surface treatments tested, alter the surface morphology, removing the epoxy matrix of fiber posts partially, exposing the glass fibers and indicating its partial corrosion.