Does water level affect benthic macro-invertebrates of a marginal lake in a tropical river-reservoir transition zone?

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Seal, replacement or monitoring amalgam restorations with occlusal marginal defects? Results of a 10-year clinical trial

The aim of this prospective and blind clinical trial was to assess the effectiveness of sealing localized marginal defects of amalgam restoration that were initially scheduled to be replaced. A cohort of twenty six patients with 60 amalgam restorations (n=44Class I and n=16Class II), that presented marginal defects deviating from ideal (Bravo) according to USPHS criteria, were assigned to either sealing or replacement groups: A: sealing n=20, Replacement n=20, and no treatment (n=20). Two blind examiners evaluated the restorations at baseline (K=0.74) and after ten years (K=0.84) according with USPHS criteria, in four parameters: marginal adaptation (MA), secondary caries (SC), marginal staining (MS) and teeth sensitivity (TS). Multiple comparison of restorations degradation/upgrade was analyzed by Friedman test and the comparisons within groups were performed by Wilcoxon test. After 10 years, 44 restorations were assessed (73.3%), Group A: n=14 and Group B: n=16; and Group C: n=14 sealing and replacement amalgam restorations presented similar level of quality in MA (p=0.76), SC (p=0.25) and TS (p=0.52), while in MS (p=0.007) presented better performance in replacement group after 10-years. Most of the occlusal amalgam restorations with marginal gaps showed similar long term outcomes than the restorations were sealed, replaced, or not treated over a 10-year period. Most of the restorations of the three groups were clinically acceptable, under the studied parameters. All restorations had the tendency to present downgrade/deterioration over time.

Efeito dos lasers de Nd:YAG e de Er:YAG na adaptação das obturações de canais radiculares: análise do selamento marginal apical

Pós-graduação em Odontologia Restauradora - ICT

Avaliação do selamento de ápices radiculares retrobturados ou recobertos com diferentes materiais mediante infiltração marginal por corante e análise da interface em microscopia eletrônica de varredura

The purpose of this study was to evaluate the apical sealing ability and the marginal adaptation of five dental materials used in retrofillings or applied to the bevelled root surface. One hundred and forty extracted single rooted human teeth were used, divided into seven groups of twenty each. ln the first, second, third and fourth groups, the teeth were apicoectomized, submitted to cavity preparations and retrofilled with one of the following materiais: zinc free silver amalgam, a dentin bonding system plus composite resin, a glass ionomer cement ora compomer. In the fifth, sixth and seventh groups, the teeth were apicoectomized and capped on the bevelled root surface with one of the following materiais: a dentin bonding system plus composite resin, a glass ionomer cement or a compomer. Two specimens of each experimental group were evaluated for the marginal adaptation using scanning electron microscopy. The remaining 126 specimens were immersed in 2% methylene blue dye, stored for one week at 37ºC and the infiltration was evaluated with a stereomicroscope. The results showed that the glass ionomer cement presented the lowest values of marginal infiltration when used as retrofilling material, with a significant statistical difference when compared with the others tested materials. When used as apical capping, the glass ionomer cement and the compomer were equivalent and significantly better than the dentin bonding system plus composite resin. Using scanning electron microscopy, all the materials showed some slight adjustment problem. ln the retrofilling, the smallest marginal gaps were observed with the compomer and the dentin bonding system plus composite resin, while the largest were observed with the glass ionomer cement and zinc free silver amalgam. ln the apical capping, the smallest marginal gaps were observed with the compomer and the dentin bonding system plus composite resin and ...

Marginal deterioration of the silicone for facial prosthesis with pigments after effect of storage period and chemical disinfection

The failure of facial prostheses is caused by limitations in the properties of existing materials, especially flexibility and durability. Therefore, this study evaluated the marginal deterioration of a silicone used for fabrication of facial prostheses (Silastic MDX4-4210, Dow Corning Corporation, Midland, MI, USA) according to the influence of artificial aging, daily disinfection, and 2 types of pigmentation. Thirty specimens were fabricated and subdivided in 6 groups: without pigmentation, pigmented with make-up powder and iron oxide, and evaluated with and without the action of the disinfectant. Analysis of marginal deterioration was performed on a scanning electron microscope (magnification, ×5000) immediately 6 months and 1 year after fabrication of specimens, following the guidelines of ASTM International. After visual analysis of the photomicrographs, it was noticed that all groups presented marginal deterioration and alterations in surface texture with time. The use of disinfection did not contribute to the marginal deterioration of polymer (silicone), regardless of the pigmentation and artificial aging.

Avaliação da infiltração marginal de três cimentos endodônticos após preparo para retentor de acordo com o momento do preparo

Objetivo: o objetivo desse estudo in vitro foi avaliar a infiltração marginal coronária após o preparo para retentor em dentes obturados com três diferentes cimentos, de acordo com o período entre a obturação do canal radicular e o preparo para retentor. Métodos: Noventa dentes humanos recentemente extraídos foram limpos e instrumentados e, então, obturados com Sealapex, Endométhasone ou TopSeal. Brocas Gates-Glidden foram utilizadas para o preparo imediato de 10 dentes de cada cimento até manter 5mm de obturação remanescente. Sessenta raízes obturadas foram incubadas a 37°C em meio úmido por 30 e 60 dias para serem, depois, preparadas para os retentores como descrito anteriormente. A superfície externa de cada raiz foi coberta com Araldite. Os espécimes foram imersos em corante azul de metileno a 2% sob vácuo por 24h, para então poderem ser analisados. A infiltração foi mensurada pelo software Sigma Scan da parte superior da obturação à porção apical alcançada pelo corante. Resultado: o Sealapex e o TopSeal apresentaram menor infiltração após o preparo para retentor do que o Endométhasone. O preparo imediato para o retentor apresentou menor infiltração do que o preparo para o retentor após 30 e 60 dias da obturação do canal radicular.

Análise da efetividade de polimerização, adaptação marginal e interna de restaurações Classe II de resinas compostas de inserção em bloco utilizando diferentes matrizes

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Colonização bacteriana na região marginal de restaurações cerâmicas: efeito do método de remoção do cimento e do polimento

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)