42 research outputs found

    Estudo da adaptação marginal de amalgamas de prata sob a influencia de ligas, triturações e brunidura

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    Orientador : Luiz Antonio RuhnkeDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de PiracicabaResumo: O objetivo desse trabalho foi verificar o nivel de adaptação da superfície da parede lateralde corpos de prova onfeccionados em amâlgamas de prata. Foram realizados corpos de prova através de três ligas de prata _diferentes, cujos nomes comerciais foram Novo True Dentalloy, Novaloy e Sybraloy. - Essas ligas foram trituradas mecanicamente e manualmente, conforme Especificação n9 1 da Associação Dentaria Americana e condéns adas com condensadór tipo Hollemback n 9 1, sob pressão de 1 kgf, de maneira convencional-e associada -a brunidura, em cavidades preparadas em dentes humanos extraídos e em matriz metâlica...Observação: O resumo, na integra, podera ser visualizado no texto completo da tese digitalAbstract: The purpose of this work was to verify thesu! face adaptation of the lateral wall of silver amalgam specimens. The specimens were developed through three different silver alloys, whDse commercial names were: Novo True Dental loy, Navaloy and Sybraloy. These alloys were triturated mechanically or manually according to American Dental Association specification n~ 1. The alloys were condensed with Hollemback condenser n9 -I under compression of 1 kgf, by conventional way and associated to the burnishing in prepared cavties of recem-extracted human teeth and metallic matrix...Note: The complete abstract is available with the full electronic digital thesis or dissertationsMestradoMateriais DentariosMestre em Odontologi

    Rugosidade e pigmentação superficial de materiais ionoméricos

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    The aim of this study was to compare two methods of surface roughness analysis, perfilometry and spectrophotometry, applied to the surface of ionomeric materials (Chelon Fil, Vitremer and Dyract), submitted to different surface finishing treatments. For the perfilometric analysis, sixty specimens of each material were made and randomly separated into three experimental groups. The average surface roughness (Ra, mm) was measured on each specimen by a surface perfilometer (Mitutoyo Surftest 211). The spectrophotometric analysis consisted in quantifying the dye impregnated in the samples. The dyes used were 0.5% fuchsin and 0.5% erythrosin. Data were submitted to variance analysis (ANOVA) and t-Student test at a 0.05 significance level. There was no linear correlation between average roughness and superficial deposition of dye. Perfilometric analysis revealed that 12- and 30-bladed carbide burs caused the roughest surface of Chelon Fil, followed by Sof-Lex discs and mylar band. There were no significant differences between the specimens submitted to finishing and polishing with Sof-Lex discs and the control group (mylar band) for Vitremer, nevertheless, the highest Ra values were obtained when 12- and 30-bladed burs were used. For Dyract, there was no significant difference between the three treatments. The mean values of superficial deposition of dye for Chelon Fil, Vitremer and Dyract were: 1.7261, 1.4759, 1.3318, respectively. There were no significant differences between the restorative materials when different finishing and polishing systems were used.O objetivo deste trabalho, in vitro, foi comparar dois métodos de análise de superfície, a rugosimetria e a espectrofotometria, aplicados a três materiais ionoméricos quando submetidos a diferentes tratamentos superficiais de acabamento e polimento. Para a análise de superfície, 60 corpos-de-prova de cada material (Chelon Fil, Vitremer e Dyract) foram confeccionados e divididos aleatoriamente em 3 grupos experimentais. A superfície dos corpos-de-prova foi avaliada por um rugosímetro, sendo obtida uma média de rugosidade. A análise espectrofotométrica consistiu na quantificação de corante impregnado na superfície do material de acordo com os grupos experimentais. Os corantes utilizados foram a fucsina básica 0,5% e a eritrosina 0,5%. Os dados foram submetidos à análise de variância e teste t de Student em nível de 5%. Os resultados mostraram não haver correlação linear confiável entre os dois métodos utilizados. Verificou-se que as brocas "carbide" produziram a maior rugosidade para o material Chelon Fil, seguido dos tratamentos com discos Sof-Lex e tira matriz. Para o Vitremer, não houve diferença entre o acabamento e polimento com discos Sof-Lex e o grupo controle (tira matriz). Os diferentes tratamentos superficiais produziram superfícies semelhantes para o material Dyract. As médias de deposição superficial de corante para Chelon Fil, Vitremer e Dyract foram: 1,7261, 1,4759, 1,3318, respectivamente, considerando p < 0,05. No entanto, os materiais comportaram-se de forma semelhante quando diferentes sistemas de acabamento e polimento foram utilizados

    Roughness and superficial staining of ionomeric materials

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    The aim of this study was to compare two methods of surface roughness analysis, perfilometry and spectrophotometry, applied to the surface of ionomeric materials (Chelon Fil, Vitremer and Dyract), submitted to different surface finishing treatments. For the perfilometric analysis, sixty specimens of each material were made and randomly separated into three experimental groups. The average surface roughness (Ra, mm) was measured on each specimen by a surface perfilometer (Mitutoyo Surftest 211). The spectrophotometric analysis consisted in quantifying the dye impregnated in the samples. The dyes used were 0.5% fuchsin and 0.5% erythrosin. Data were submitted to variance analysis (ANOVA) and t-Student test at a 0.05 significance level. There was no linear correlation between average roughness and superficial deposition of dye. Perfilometric analysis revealed that 12- and 30-bladed carbide burs caused the roughest surface of Chelon Fil, followed by Sof-Lex discs and mylar band. There were no significant differences between the specimens submitted to finishing and polishing with Sof-Lex discs and the control group (mylar band) for Vitremer, nevertheless, the highest Ra values were obtained when 12- and 30-bladed burs were used. For Dyract, there was no significant difference between the three treatments. The mean values of superficial deposition of dye for Chelon Fil, Vitremer and Dyract were: 1.7261, 1.4759, 1.3318, respectively. There were no significant differences between the restorative materials when different finishing and polishing systems were used.O objetivo deste trabalho, in vitro, foi comparar dois métodos de análise de superfície, a rugosimetria e a espectrofotometria, aplicados a três materiais ionoméricos quando submetidos a diferentes tratamentos superficiais de acabamento e polimento. Para a análise de superfície, 60 corpos-de-prova de cada material (Chelon Fil, Vitremer e Dyract) foram confeccionados e divididos aleatoriamente em 3 grupos experimentais. A superfície dos corpos-de-prova foi avaliada por um rugosímetro, sendo obtida uma média de rugosidade. A análise espectrofotométrica consistiu na quantificação de corante impregnado na superfície do material de acordo com os grupos experimentais. Os corantes utilizados foram a fucsina básica 0,5% e a eritrosina 0,5%. Os dados foram submetidos à análise de variância e teste t de Student em nível de 5%. Os resultados mostraram não haver correlação linear confiável entre os dois métodos utilizados. Verificou-se que as brocas carbide produziram a maior rugosidade para o material Chelon Fil, seguido dos tratamentos com discos Sof-Lex e tira matriz. Para o Vitremer, não houve diferença entre o acabamento e polimento com discos Sof-Lex e o grupo controle (tira matriz). Os diferentes tratamentos superficiais produziram superfícies semelhantes para o material Dyract. As médias de deposição superficial de corante para Chelon Fil, Vitremer e Dyract foram: 1,7261, 1,4759, 1,3318, respectivamente, considerando p < 0,05. No entanto, os materiais comportaram-se de forma semelhante quando diferentes sistemas de acabamento e polimento foram utilizados.351356Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

    Effects of acids used in the microabrasion technique: microhardness and confocal microscopy analysis

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    Background: This study evaluated the effects of the acids used in the microabrasion on enamel. Material and Methods: Seventy enamel/dentine blocks (25 mm 2 ) of bovine incisors were divided into 7 groups (n=10). Experimental groups were treated by active/passive application of 35% H 3 PO 4 (E1/E2) or 6.6% HCl (E3/ E4). Control groups were treated by microabrasion with H 3 PO 4 +pumice (C5), HCl+silica (C6), or no treatment (C7). The superficial (SMH) and cross-sectional (CSMH; depths of 10, 25, 50, and 75 μm) microhardness of enamel were analyzed. Morphology was evaluated by confocal laser-scanning microscopy (CLSM). Data were analyzed by analysis of variance (Proc Mixed), Tukey, and Dunnet tests (α=5%). Results: Active application (E1 and E3) resulted in higher microhardness than passive application (E2 and E4), with no difference between acids. For most groups, the CSMH decreased as the depth increased. All experimental groups and negative controls (C5 and C6) showed significantly reduced CSMH values compared to the control. A significantly higher mean CSMH result was obtained with the active application of H 3 PO 4 (E1) compared to HCl (E3). Passive application did not result in CSMH differences between acids. CLSM revealed the conditioning pattern for each group. Conclusions: Although the acids displayed an erosive action, use of microabrasive mixture led to less damage to the enamel layer

    Effect of light curing modes and ethanol immersion media on the susceptibility of a microhybrid composite resin to staining

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    The aim of this in vitro study was to evaluate the susceptibility of a hybrid composite resin (Filtek Z250 - 3M ESPE) to staining, when light cured in four different modes and immersed in two different media. Composite resin specimens were randomly prepared and polymerized according to the experimental groups (conventional - 550 mW/cm² / 30 seconds; soft start - 300mW/cm² / 10 seconds + 550 mW/cm² / 20 seconds; high intensity - 1060 mW/cm² - 10 seconds; pulse delay - 550 mW/cm² - 1 seconds + 60 seconds of waiting time + 550 mW/cm² - 20 seconds) and immersed in one of two media (distilled water or absolute ethanol) for 24h. Next, the specimens were immersed in a 2% methylene blue solution for 12 hours. Afterwards, the specimens were washed and prepared for the spectrophotometric analysis. For statistical analysis, two-way ANOVA (4X2) and Tukey's test were performed on the data at 0.05 confidence level. Soft start showed the least staining, and was statistically different from the high intensity and pulse delay light curing modes (p;0.05). There were no significant differences between the two immersion media (p>;0.05). The soft start polymerization mode showed lower susceptibly of the composite resin to staining than high intensity and pulse delay, irrespective of the immersion medium

    Advances In Dental Veneers: Materials, Applications, And Techniques.

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    Laminate veneers are a conservative treatment of unaesthetic anterior teeth. The continued development of dental ceramics offers clinicians many options for creating highly aesthetic and functional porcelain veneers. This evolution of materials, ceramics, and adhesive systems permits improvement of the aesthetic of the smile and the self-esteem of the patient. Clinicians should understand the latest ceramic materials in order to be able to recommend them and their applications and techniques, and to ensure the success of the clinical case. The current literature was reviewed to search for the most important parameters determining the long-term success, correct application, and clinical limitations of porcelain veneers.49-1

    Effectiveness of dental bleaching in depth after using different bleaching agents

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    Objectives: This study evaluated the effectiveness of low- and high-concentration bleaching agents on enamel and deep dentin. Study design: Stained bovine incisors fragments were randomized placed into 10 groups (n=5), according to the sample thicknesses (2.0 mm or 3.5 mm) and bleaching agent: 10% carbamide peroxide (CP) (4 h a day/21 days); 6% hydrogen peroxide (HP) with calcium (1:30 h a day/21 days); HP 20% with calcium (50 min a day/3 sessions with a 7-day interval); HP 35% (3 x 15 min a day/3 sessions with a 7-day interval); HP 35% with calcium (40 min a day/3 sessions with a 7-day interval). The samples were stored in artificial saliva during the experiment. The co - lor change was evaluated using a spectrophotometer at the initial analysis, after artificially staining with black tea and after each of the bleaching weeks, and data was expressed in CIE Lab System values. The L* coordinate data was submitted to analysis of variance and Tukey-Kramer test and the ?E values data was submitted for analysis of variance in a split-plot ANOVA and Tukey's test (?=0.05). Results: None of the bleaching agents tested differed from the reflectance values on the enamel surface. For deep dentin HP 20% and HP 35%, both with calcium, showed the lowest reflectance values, which differed from CP 10%. Conclusion: It is concluded that high concentration hydrogen peroxide with calcium was less effective in deep dentin than 10% carbamide peroxide

    In situ assessment of the saliva effect on enamel morphology after microabrasion technique

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    AIM: This study evaluated saliva effects on enamel morphology surface after microabrasion technique. METHODS: Enamel blocks (16 mm2) obtained from bovine incisors were divided into 9 groups as follows: one control group (no treatment), four groups with microabrasion treatment using 35% phosphoric acid and pumice (H3PO4+Pum) and other four groups treated with 6.6% hydrochloric acid and silica (HCl+Sil). One group of each treatment was submitted to 4 frames of saliva exposure: without exposure, 1-h exposure, 24-h exposure, and 7-days exposure on in situ regimen. Nineteen volunteers (n=19), considered as statistical blocks, used an intraoral appliance containing the specimens, for 7 days. Enamel roughness (Ra) was tested before and after treatment, and after saliva exposure. Confocal laser scanning microscopy (CLSM) was used to evaluate qualitatively the enamel morphology. RESULTS: All groups exhibited increased Ra after microabrasion. With regards to saliva exposure, the treatment with HCl+Sil presented more susceptibility to the saliva action, but no period of time was efficient in re-establishing this characteristic compared with the control group. CLSM analysis showed reduction of the micro-abrasive damages during the experimental times. CONCLUSIONS: Seven days of saliva exposure were not sufficient for the treated enamel to reach its normal characteristics compared with the control group133187192FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP2011/004067-

    Influence of surface treatments on enamel susceptibility to staining by cigarette smoke

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    Objectives: The purpose of this study was to evaluate the influence of remineralizing agents, including artificial saliva, neutral fluoride, and casein phosphopeptide-amorphous calcium phosphate (CPP-ACP), on the susceptibility of bleached enamel to staining by cigarette smoke. Study design: Fifty bovine enamel blocks were randomly divided into five groups (n = 10): G1- bleaching; G2- bleaching and immersion in artificial saliva; G3- bleaching and application of CPP-ACP; G4- bleaching and application of neutral fluoride; and G5- untreated (Control). Teeth were bleached with 35% hydrogen peroxide and treated with the appropriate remineralizing agent. After treatment, all groups were exposed to cigarette smoke. Enamel color measurements were performed at three different times: before treatment (T1), after treatment (bleaching and remineralizing agent) (T2), and after staining (T3), by using the CIE Lab method with a spectrophotometer. The data coordinate L* was evaluated by analysis of repeated-measures PROC MIXED and Tukey-Kramer's test, and the ?E values were submitted to one-way ANOVA and Tukey¿s test (? = 0.05). Results: The G1 group did not show any statistically significant difference for L* values between times T1 and T2. The G4 and G5 groups showed lower L* values at T3 compared to T2. No significant differences between the groups were observed for ?E (after treatment and staining). However, G4 showed a clinically apparent color change. Conclusions: Treatment of bleached enamel with neutral fluoride can contribute to the increased staining of enamel due to cigarette smoke
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