IMPROVEMENT TO THE MARGINAL COPING FIT of COMMERCIALLY PURE TITANIUM CAST IN PHOSPHATE-BONDED INVESTMENT BY USING A SIMPLE PATTERN COATING TECHNIQUE

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Evaluation of marginal microleakage in Class II cavities: Effect of microhylolrid, flowable, and compactable resins

Objective: the goal of the present study was to evaluate the microleakage on the cementum/dentin and enamel surfaces in Class 11 restorations, using different kinds of resin composite (microhybrid, flowable, and compactable). Method and materials: Forty human caries-free molars were extracted and selected. Eighty Class 11 standardized cavities were made in the cervical wall at the cementoenamel junction (CEJ) and at the mesial and distal surfaces. The teeth were divided into four groups: G1 - adhesive system + microhybrid resin composite Z100; G2 - adhesive system + compactable resin composite Prodigy Condensable; G3 - adhesive system + flowable resin composite Revolution + Z1 00 resin composite; G4 - adhesive system + Revolution fluid resin + compactable resin composite Prodigy Condensable. The adhesive system used in this study was Scotchbond Multi-Purpose Plus. The specimens were thermocycled in baths of 5degreesC and 55degreesC for 1,000 cycles and immersed in 50% silver nitrate solution. The specimens then were sectioned and evaluated on degree of dye penetration. Results: the results were evaluated using the nonparametric Kruskall-Wallis test, which showed a statistically significant difference between groups G1 and G4, G2 and G4, and G3 and G4. Conclusions: None of the materials was able to eliminate the marginal microleakage at the cervical wall; the application of a low-viscosity resin composite combined with a compactable resin composite significantly decreased the microleakage.

Marginal gingiva discoloration by gray MTA: A case report

Perforation of the root canal during insertion of an intracanal post is a complication of endodontic therapy. Mineral trixoide aggregate (MTA) has been successfully used a sealer in these situations. This material has recently been formulated in white color, allowing its application in areas of esthetic concern. This is a clinical case report of a root perforation sealed with gray MTA that resulted in discoloration of the marginal gingiva. Treatment consisted of replacing gray MTA with white MTA with the aid of a dental operating microscope, producing satisfactory esthetic results.

Accuracy of Digital Images in the Detection of Marginal Micro leakage: An In Vitro Study

Purpose: To evaluate the accuracy of Image Tool Software 3.0 (ITS 3.0) to detect marginal microleakage using the stereomicroscope as the validation criterion and ITS 3.0 as the tool under study.Materials and Methods: Class V cavities were prepared at the cementoenamel junction of 61 bovine incisors, and 53 halves of them were used. Using the stereomicroscope, microleakage was classified dichotomously: presence or absence. Next, ITS 3.0 was used to obtain measurements of the microleakage, so that 0.75 was taken as the cut-off point, and values equal to or greater than 0.75 indicated its presence, while values between 0.00 and 0.75 indicated its absence. Sensitivity and specificity were calculated by point and given as 95% confidence interval (95% CI).Results: The accuracy of the ITS 3.0 was verified with a sensitivity of 0.95 (95% CI: 0.89 to 1.00) and a specificity of 0.92 (95% CI: 0.84 to 0.99).Conclusion: Digital diagnosis of marginal microleakage using ITS 3.0 was sensitive and specific.

THE EFFECT of IMMEDIATE DENTIN SEALING on THE MARGINAL ADAPTATION and BOND STRENGTHS of TOTAL-ETCH and SELF-ETCH ADHESIVES

Statement of problem. Sealing ability and bond strengths of total-etch and self-etch dentin adhesives used for immediate dentin sealing have not been assessed and established.Purpose. The purpose of this study was to determine the effectiveness of immediate dentin sealing (IDS) using total-etch or self-etch dentin adhesives on microleakage and microtensile bond strength.Material and methods. Twenty recently extracted molars were selected, and standard MOD inlay preparations were made with the gingival margins located below the cemento-enamel unction. The teeth were assigned to 4 experimental groups (n=5) according to the indirect composite restoration cementation technique used: (1) immediate dentin sealing with Adper Single Bond (TEBI); (2) conventional adhesive cementation technique using Adper Single Bond (TEAI); (3) immediate dentin sealing using Adper Prompt L-Pop (SEBI); or (4) conventional adhesive cementation technique using Adper Prompt L-Pop (SEAI). The restored teeth were thermal cycled 1,000 times between 5 degrees and 55 degrees C and then immersed in 50% ammoniacal silver nitrate. Three specimens per restoration were evaluated for microleakage, according to predefined scores, and submitted to Friedman's test (alpha-.05). The specimens were then sectioned to obtain 0.8 +/- 0.2-mm-thick sticks (with n ranging from 32 to 57 specimens) and submitted to microtensile bond strength (mu TBS) testing. The obtained data were submitted to 2-way ANOVA test (alpha=.05).Results. None of the experimental groups demonstrated complete elimination of marginal microleakage. There were significant differences in microleakage of the tested adhesives (P>.001). IDS microleakage scores were similar to those obtained using the conventional cementation technique (CCT) for both adhesives. The highest mean bond strengths were obtained with TEBI (51.1 MPa), whereas SEAI showed the lowest mean bond strengths (1.7 MPa). IDS resulted in significantly higher bond strengths than CCT (P<.001).Conclusions. Total-etch and self-etch adhesives have a significant effect on IDS. IDS resulted in high bond strengths for both adhesives; however, the microleakage was similar to that obtained with CCT (J Prosthet Dent 2009;102:1-9)

Marginal adaptation of Class 2 adhesive restorations

Objective: Control of microleakage represents a challenge for posterior composite restorations. The technique for composite placement may reduce microleakage. The null hypothesis of this in vitro study was that centripetal incremental insertion of composite resin would result in less microleakage than that obtained with the oblique incremental technique or bulk technique. Method and Materials: Standardized Class 2 preparations were made in 60 caries-free extracted third molars and randomly assigned to 3 groups ( n = 20): ( 1) oblique incremental insertion technique ( control), ( 2) centripetal incremental insertion technique, and ( 3) bulk insertion. The teeth were restored with a total-etch adhesive and micro-hybrid composite resin. The specimens were isolated with nail varnish except for a 2-mm-wide area around the restoration and then thermocycled ( 1,000 thermal cycles, 5 degrees C/ 55 degrees C; 30-second dwell time). The specimens were immersed in an aqueous solution of 50% silver nitrate for 24 hours, followed by 8 hours of immersion in a photo-developing solution and subsequently evaluated for leakage. The microleakage scores ( 0 to 4) obtained from the occlusal and cervical walls were analyzed with median nonparametric tests ( P <.05). Results: The null hypothesis was rejected. All techniques attained statistically similar dentin microleakage scores ( P =.15). The centripetal insertion technique displayed significantly less microleakage than the oblique technique at the enamel margins ( P =.04). Conclusion: None of the techniques eliminated marginal microleakage in Class 2 preparations. However, in occlusal areas, the centripetal technique performed significantly better than the other techniques.

Composição e distribuição dos Crustácea (Decapoda) na Lagoa do Peixe, Rio Grande do Sul, Brasil

The Lagoa do Peixe (Peixe's Lagoon) is located between Atlantic Ocean and Lagoa dos Patos and is 30 Km long and 0,5-2,0 Km wide (31º13'S, 50º55'W -31º26'S, 51º09'). For one year, the composition and distribution of Crustácea Decapoda were analyzed monthly (from July/1994 to June/1995), in seven subareas (terrestrial border and aquatic area) and physical and chemical parameters (depth, salinity, sediment texture, oxygen in water, organic material of sediment and water temperature) were registered. Decapoda from the families Grapsidae, Ocypodidae, Portunidae (Brachyura), Diogenidae (Anomura) and Penaeidae (Penaeidea) were captured. Chasmagnathus granulata Dana 1851 was found ali months near the canal connecting Atlantic Ocean and Lagoa do Peixe, but inside the lagoon it was collected only in October/94 and June/95, and in extreme subareas it was sampled in February/95 when the salinity was 31 at these sites. Callinectes sapidus Rathbun, 1896 and Cyrtograpsus angulatus Dana, 1851 were captured throughout the year, except October/94 and April/95, respectively. Both species were found in ali áreas of sample, indicating a high plasticity in relation to the factors analyzed in this study. Another species captured probably come in the lagoon in specific months, when the environment provides ideal conditions for their develo-pments.

Diet of the ichthyofauna associated with marginal vegetation of a mangrove forest in southeastern Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Rotifer abundance, biomass, and secondary production after the recovery of hydrologic connectivity between a river and two marginal lakes (São Paulo, Brazil)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Occurrence of Pseudosida ramosa Daday, 1904 (Crustacea: Cladocera: Ctenopoda) in marginal lakes of the Paranapanema River, with comments on its distribution.

Aim: Contribute to the understanding of the distribution of a littoral cladoceran, Pseudosida ramosa Daday, 1904, in Brazil, with special reference for the Paranapanema River basin (Southeast Brazil); Methods: The specimens were sampled in two floodplain lakes located in the middle Paranapanema River basin, in the boundary of São Paulo and Parana States, using a standard plankton net (50 [mu]m mesh size). Trinocular microscopic with camera lucida and milimetric scale was used for the observation and measurements of the specimens; Results: Only three individuals were found (in winter and summer), despite of an extensive sampling program during 17 consecutive months of observations in both lakes. The largest body length was 1,146 [mu]m. The taxonomical identification followed Korovchinsky (1992); Conclusions: This species have a wide geographical distribution in Brazil, but it is restricted to zones colonized by aquatic macrophytes and seems to occur in low population abundance. The scarcity of registers of P. ramosa demonstrates the necessity of deeper investigations of littoral habits as well as the important role of this kind of environment for the conservation of the rivers/reservoirs biota, including some possible rare species.

Composição e abundância da ictiofauna de duas lagunas costeiras da América do Sul Austral: lagoa do Peixe (31ºS; 51ºW), Brasil e laguna Mar Chiquita (37ºS; 57ºW), Argentina

This article describes and compares the shallow water fish-fauna from two coastal lagoons (Peixe Lagoon, in Brazil, and Mar Chiquita Lagoon, in Argentina). Peixe Lagoon was sampled between 2000 and 2001 using a 9 m beach seine net (12 mm bar mesh in the wings and 5 mm in the centre 3 m section) totalizing 125 samples, which yielded 33,848 individuals and 32 species. Mar Chiquita Lagoon was sampled from 1995 to 1998 using a 21) m beach seine net (12 mm bar mesh) totalizing 232 samples resulting in 31,097 individuals of 28 species. A total of 47 species were observed in both lagoons and 13 were shared. The "marine-estuarine-related" species were similar and dominate the fish assemblages in both lagoons. The remaining species were similar to the species collected along the southern Brazil, Uruguay and Argentina estuaries. The number of species observed in Peixe Lagoon (S = 32) was higher than in Mar Chiquita Lagoon (S = 28) and is probably associated with a strong latitudinal gradient of species richness increasing from north to south. Considering that the Peixe Lagoon and Mar Chiquita Lagoon are isolated by the large estuaries of Patos Lagoon and Prata River, the composition of the species with low abundance and occasional occurrence were different for each local studied. These results expand the knowledge for the fauna of both sites and help conservation and management from both lagoons.

Avaliação (em escala laboratorial) da aplicação do processo eletrolítico em efluente de lagoa de estabilização de esgoto urbano

Physico-chemical and microbiological parameters were evaluated before and after applying an electrolytic process to effluents of a stabilization lagoon, in the presence or absence of salt. Chlorine generation and bactericidal properties of the treatments were studied following two experiments. Effluent pH increased with electrolysis time. In the absence of salt, 20 min electrolysis resulted in a COD (Chemical Oxygen Demand) reduction of 44%, along with ca. 99.9% (3 log10 cfu/mL) reduction in total coliforms, heterotrophic bacteria and Escherichia coli. These results indicated that the electrolytic process is a promising complementary technology to improve effluent quality for stabilization lagoons.

Marginal and Internal Discrepancies Related to Margin Design of Ceramic Crowns Fabricated by a CAD/CAM System

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)