Crop wild relatives of the United States require urgent conservation action.

The contributions of crop wild relatives (CWR) to food security depend on their conservation and accessibility for use. The United States contains a diverse native flora of CWR, including those of important cereal, fruit, nut, oil, pulse, root and tuber, and vegetable crops, which may be threatened in their natural habitats and underrepresented in plant conservation repositories. To determine conservation priorities for these plants, we developed a national inventory, compiled occurrence information, modeled potential distributions, and conducted threat assessments and conservation gap analyses for 600 native taxa. We found that 7.1% of the taxa may be critically endangered in their natural habitats, 50% may be endangered, and 28% may be vulnerable. We categorized 58.8% of the taxa as of urgent priority for further action, 37% as high priority, and 4.2% as medium priority. Major ex situ conservation gaps were identified for 93.3% of the wild relatives (categorized as urgent or high priority), with 83 taxa absent from conservation repositories, while 93.1% of the plants were equivalently prioritized for further habitat protection. Various taxonomic richness hotspots across the US represent focal regions for further conservation action. Related needs include facilitating greater access to and characterization of these cultural-genetic-natural resources and raising public awareness of their existence, value, and plight.

Data for the calculation of an indicator of the comprehensiveness of conservation of useful wild plants.

The datasets and code presented in this article are related to the research article entitled "Comprehensiveness of conservation of useful wild plants: an operational indicator for biodiversity and sustainable development targets"1. The indicator methodology includes five main steps, each requiring and producing data, which are fully described and available here. These data include: species taxonomy, uses, and general geographic information (dataset 1); species occurrence data (dataset 2); global administrative areas data (dataset 3); eco-geographic predictors used in species distribution modeling (dataset 4); a world map raster file (dataset 5); species spatial distribution modeling outputs (dataset 6); ecoregion spatial data used in conservation analyses (dataset 7); protected area spatial data used in conservation analyses (dataset 8); and countries, sub-regions, and regions classifications data (dataset 9). These data are available at http://dx.doi.org/10.17632/2jxj4k32m2.1. In combination with the openly accessible methodology code (https://github.com/CIAT-DAPA/UsefulPlants-Indicator), these data facilitate indicator assessments and serve as a baseline against which future calculations of the indicator can be measured. The data can also contribute to other species distribution modeling, ecological research, and conservation analysis purposes.

Pteridofitas: helechos y licófitos de El mundo vegetal de los Andes peruanos en el contexto actual / Pteridophytes: Ferns and lycophytes of El mundo vegetal de los Andes peruanos in the current context

Resumen Los helechos y licófitos mencionados en El mundo Vegetal de los Andes peruanos de Weberbauer brindan una breve información de su riqueza y sustento a las observaciones ambientales para cada categoría de su esquema fitogeográfico del Perú. Este estudio actualiza tanto el concepto y características de los pteridofitos mencionados en el capítulo Unidades Sistemáticas, como la nomenclatura de los 126 nombres de los taxones mencionados en la obra. Además, se ofrece una breve historia del estudio del grupo en el Perú, para proveer el contexto de la inclusión de estas plantas por Weberbauer. Y se mencionan las colecciones que Weberbauer realizara del grupo y, en particular, las citadas como ejemplos. Se ofrece un perfil de las tareas por realizar para completar la labor biogeográfica iniciada por Weberbauer.

Abstract Ferns and lycophytes were mentioned by Weberbauer in his El mundo Vegetal de los Andes peruanos to provide a hint of the richness of the group and to support his natural history observations for each category of his phytogeographic description of Peru. This contribution updates concepts and features of these plants as discussed in the chapter on "Systematic Units" and updates the 126 names of taxa cited in his book. To this end, we provide a brief history of the development of Peru's pteridoflora studies in the context of Weberbauer's work. We also document Weberbauer's pteridophyte collections linked to the verification of the taxa of his examples. A framework for future research is provided to complete the biogeographic endeavor that begun with his work and highlights the need to relocate his plant collections as witnesses of his legacy.

An integrated assessment of the vascular plant species of the Americas.

The cataloging of the vascular plants of the Americas has a centuries-long history, but it is only in recent decades that an overview of the entire flora has become possible. We present an integrated assessment of all known native species of vascular plants in the Americas. Twelve regional and national checklists, prepared over the past 25 years and including two large ongoing flora projects, were merged into a single list. Our publicly searchable checklist includes 124,993 species, 6227 genera, and 355 families, which correspond to 33% of the 383,671 vascular plant species known worldwide. In the past 25 years, the rate at which new species descriptions are added has averaged 744 annually for the Americas, and we can expect the total to reach about 150,000.

Avaliação dos tratamentos de superfície na resistência de união entre dois pinos de fibra de vidro e uma resina composta / Evaluation of surface treatments on the bond strength between two fiberglass posts and a composite resin

Introdução: O objetivo deste trabalho foi avaliar a influência de diferentes métodos de tratamento de superfície em pinos de fibra de vidro com relação a sua força de união com a resina composta e avaliar os tipos de falhas ocorridas. Materiais e Métodos: Foram utilizados 36 pinos da WhitepostDC (grupo GF) e Exacto Cônicos (grupo GA), divididos em: Grupos controle GF-1 e GA-1 ­ aplicação de silano de acordo com as especificações do fabricante; Grupos GF-2 e GA-2 ­ condicionamento com peróxido de hidrogênio a 10% e silanização; Grupos GF-3 e GA-3 ­ Jateamento com óxido de alumínio por 10 segundos e silanização. A adição da resina composta foi realizada em incrementos de 2 mm, com fotopolimerização de cada incremento por 40 segundos, até o preenchimento de toda extensão da matriz. Então, o conjunto pino e resina composta foi seccionado em três porções (cervical, médio e apical) (n = 18). As amostras foram submetidas à análise de resistência de união através do teste Push-Out em uma Máquina de Ensaio Universal (EMIC), e os tipos de falhas foram avaliados com aumento 30 × com um microscópio óptico. Os dados foram submetidos à análise de variância, ao teste de Tukey e ao teste de qui-quadrado com significância de 5%. Resultados: Nos grupos GA, o tratamento com silano (23,10 MPa) resultou em resistência de união estatisticamente maior que os tratamentos com peróxido (17,19 MPa) e com jateamento (16,28 MPa). No tratamento com peróxido, a resistência de união foi estatisticamente maior no terço médio (21,16 MPa) que no terço apical (12,55 MPa). A falha do tipo mista teve a maior prevalência (57,01%). Conclusão: O tratamento com silano apresentou maior resistência de união, com diferença estatística dos demais grupos na marca Angelus

Introduction: The aim of this study was to evaluate the influence of different surface treatment methods on glass-fiber posts relative to their bond strength with the composite resin and to evaluate the types of failures that occurred. Materials and Methods: Thirty-six posts from WhitepostDC (FG group) and Exacto Conics (AG group) were used, divided into: Control FG-1 and AG-1 groups ­ application of silane, according to manufacturers' specifications; FG-2 and AG-2 groups ­ conditioning with 10% hydrogen peroxide and silanization; FG-3 and AG-3 groups ­ aluminum oxide blasting for 10 seconds and silanization. The composite resin was added in 2-mm increments, each increment was photopolymerized for 40 seconds, until the entire length of the matrix was filled. Then, the assembly (fiber post and composite resin) was sectioned into three portions (cervical, middle and apical) (n = 18). Samples were submitted to the bond strength analysis by a push-out test in a Universal Testing Machine and the failure types were evaluated with a 30 × magnification with an optical microscope. Data were submitted to the analysis of variance, the Tukey test, and the chi-square test with a 5% significance level. Results: For AG groups, the treatment with silane (23.10 MPa) resulted in statistically greater bond strength than the treatments with peroxide (17.19 MPa) and blasting (16.28 MPa). It was found that the bond strength was statistically higher in the middle third (21.16 MPa) than in the apical third (12.55 MPa) for the peroxide treatment. The mixed-type failure had the highest prevalence (57.01%).

Illicit crops and armed conflict as constraints on biodiversity conservation in the Andes region.

Coca, once grown for local consumption in the Andes, is now produced for external markets, often in areas with armed conflict. Internationally financed eradication campaigns force traffickers and growers to constantly relocate, making drug-related activities a principal cause of forest loss. The impact on biodiversity is known only in general terms, and this article presents the first regional analysis to identify areas of special concern, using bird data as proxy. The aim of conserving all species may be significantly constrained in the Santa Marta and Perijá mountains, Darién, some parts of the Central Andes in Colombia, and between the middle Marañón and middle Huallaga valleys in Peru. Solutions to the problem must address the root causes: international drug markets, long-lasting armed conflict, and lack of alternative income for the rural poor.

Cinchona L. "Árbol de la Quina": repoblamiento y reforestación en el Perú / Cinchona L. "Quina Tree": Repopulation and reforestation in Peru

Resumen Este trabajo se centra en las recientes decisiones tomadas por el Ministerio de Agricultura del Perú sobre la recolección, propagación y siembra de especies de quina. Señalamos las deficiencias de estas decisiones a la luz de los avances en el conocimiento de la taxonomía y sistemática de Cinchona. Destacamos el papel de la ciencia analizando e informando sobre las decisiones en el uso sostenible de los recursos naturales.

Abstract This work focuses about the recent decisions made by the Ministry of Agriculture of Peru on the collection, propagation, and sowing of Cinchona species are reasons to point out the deficiencies of these decisions in light of advances in the knowledge of Cinchona taxonomy and systematics. We emphasize the role of the science analysing and informing about decisions in the sustainable use of natural resources.

Confirmation of a continental-scale disjunction for the fern Campyloneurum decurrens (Polypodiaceae) / Confirmación de una disyunción a escala continental del helecho Campyloneurum decurrens (Polypodiaceae)

We confirm the presence of Campyloneurum decurrens in the western side of South America based on herbarium collections. Specifically, we report three additional localities for its geographical range, two in Peru and one in Ecuador, and provide additional morphological information on this species. This report confirms a disjunction for this species between the Atlantic Forest in southeastern Brazil and the lowland forests in the Peruvian Amazon, and in the Ecuadorean Choco.

Se confirma la presencia de Campyloneurum decurrens en el occidente de América del Sur en base a colecciones de herbario. Se reporta tres localidades adicionales para su distribución geográfica, dos en Perú y una en Ecuador y se provee de información morfológica adicional. Este reporte confirma también el patrón de disyunción entre la región del Bosque Atlántico en el sureste del Brasil y la de los bosques bajos de la amazonia peruana y del Chocó ecuatoriano.

Vascular flora and phytogeographical links of the Carabaya Mountains, Peru / Flora vascular y conexiones fitogeográficas de las montañas Carabaya, Perú

Studies of floristic composition and plant species richness in tropical mountains support their recognition as areas of high biological diversity, and therefore of their importance for plant conservation. Here, we present data on the flora of the high Andes of eight sites centered in the Carabaya mountains, and also provide a floristic comparison with nine other floras within Peru and northern Bolivia. The study area includes 506 species of vascular plants, grouped in 203 genera and 66 families. The highest species richness was found in two families: Asteraceae and Poaceae, which collectively encompass 37% of all species. Other important families were Caryophyllaceae, Fabaceae, Malvaceae, Brassicaceae, Caprifoliaceae, Gentianaceae, Plantaginaceae and Cyperaceae. The most diverse genera wereSenecio, Calamagrostis, Poa and Nototriche. Perennial herbs were the dominant growth form. The vascular flora of the Carabaya Mountains is closely related to those of other regions of southern Peru. Also, more than half of all vascular plants registered for the Carabaya Mountain occur in the Andean region of Bolivia, which shows the undoubted geophysical and phytogeographical connection of the Carabaya and the Bolivian Apolobamba Mountains. This study also shows that there is still a need for more extensive plant collecting and future exploration, since the Carabaya, as other parts of Peru’s high Andes are subject of dramatic change that may threaten these plant populations.

Los estudios sobre la composición florística y riqueza de especies en montañas tropicales apoyan su reconocimiento como áreas de alta diversidad biológica, y, por tanto, de su importancia para la conservación. En este trabajo presentamos datos sobre la flora altoandina de ocho sitios localizados en la Cordillera de Carabaya, proveemos también una comparación florística con otros nueve lugares tanto en Perú como en el norte de Bolivia. El área de estudio incluye 506 especies de plantas vasculares, reconocidas en 203 géneros y 66 familias. Las tasas más altas de riqueza de especies se hallan en dos familias: Asteraceae y Poaceae, que colectivamente abarcan el 37% de todas las especies. Otras familias importantes fueron Caryophyllaceae, Fabaceae, Malvaceae, Brassicaceae, Caprifoliaceae, Gentianaceae, Plantaginaceae y Cyperaceae. Los géneros más diversos fueron Senecio, Calamagrostis, Poa y Nototriche. La forma de crecimiento predominante fueron las hierbas perennes. La flora vascular de la Cordillera Carabaya está muy relacionada con otras regiones del sur de Perú. Además, más de la mitad de todas las plantas vasculares registradas para la Cordillera Carabaya se encuentran en la región andina de Bolivia, lo que demuestra la indudable conexión geofísica y fitogeográfica entre las cordilleras Carabaya y Apolobamba de Bolivia. Este estudio también demuestra la necesidad de una extensa colección botánica y futura exploración, desde que Carabaya, como otras partes de los altos Andes del Perú, están sujetos a cambios dramáticos que amenazan las poblaciones de esas plantas.

Push-out bond strength of glass fiber posts luted with two resin cements / Resistência à tração de pinos de fibra de vidro cimentados com dois tipos de cimento resinoso

Objectives: To evaluate the bond strength of a prefabricated glass fiber post to the root dentin with two resin cements using the push-out test. Material and Methods: Thirty fiber posts (White Post ECD) were cemented in human endodontically treated anterior teeth with two resin cements (n=15): RelyxTM ARC and AllCem. The roots were transversely sectioned and divided in cervical, middle and apical thirds after 48 h of cementation. The specimens' retention was tested by push-out method. The results were analyzed by 2-way ANOVA and Tukey's test (p <0.05). Results: There were no significant differences in the bond strength between the resin cements. The bond strength was higher in cervical third than in middle and apical thirds for both resin cements. It was observed higher percentages of adhesive failures followed by mixed. Conclusions: Both resin cements are indicated in the cementation of glass fiber post. (AU)

Objetivo: Avaliar a resistência de união entre dentina radicular e pino pré-fabricado, utilizando dois sistemas cimentantes, por meio do teste push-out. Material e Métodos: Trinta pinos de fibra de vidro (White Post DCE) foram cimentados a dentes humanos anteriores, tratados endodonticamente, com o auxílio de dois sistemas cimentantes (n=15): RelyxTM ARC e AllCem. Após 48 horas da cimentação, as raízes foram seccionadas transversalmente e divididas em terços cervical, médio e apical. Os corpos-de-prova foram submetidos ao teste de cisalhamento por extrusão "push-out". Os resultados foram submetidos aos testes estatísticos de análise de variância (2-way ANOVA) e de Tukey y (p<0,05). Resultados: Não houve diferença estatisticamente significativa na resistência de união entre os dois cimentos resinosos utilizados. A resistência de união foi maior no terço cervical do que nos terços médio e apical. Foi observada maior frequência de falhas adesivas seguida das mistas. Conclusão: Os dois cimentos resinosos são sugeridos para a cimentação de pinos de fibra de vidro (AU)

Blood glucose level neural model for type 1 diabetes mellitus patients.

This paper deals with the blood glucose level modeling for Type 1 Diabetes Mellitus (T1DM) patients. The model is developed using a recurrent neural network trained with an extended Kalman filter based algorithm in order to develop an affine model, which captures the nonlinear behavior of the blood glucose metabolism. The goal is to derive a dynamical mathematical model for the T1DM as the response of a patient to meal and subcutaneous insulin infusion. Experimental data given by continuous glucose monitoring system is utilized for identification and for testing the applicability of the proposed scheme to T1DM subjects.

Evidence of a high-Andean, mid-Holocene plant community: An ancient DNA analysis of glacially preserved remains.

PREMISE OF THE STUDY: Around the world, tropical glaciers and ice caps are retreating at unprecedented rates because of climate change. In at least one location, along the margin of the Quelccaya Ice Cap in southeastern Peru, ancient plant remains have been continually uncovered since 2002. We used genetic analysis to identify plants that existed at these sites during the mid-Holocene. • METHODS: We examined remains between 4576 and 5222 yr old, using PCR amplification, cloning, and sequencing of a fragment of the chloroplast trnL intron. We then matched these sequences to sequences in GenBank. • KEY RESULTS: We found evidence of at least five taxa characteristic of wetlands, which occur primarily at lower elevations in the region today. • CONCLUSIONS: A diverse community most likely existed at these locations the last time they were ice-free and thus has the potential to reestablish with time. This is the first genetic analysis of vegetation uncovered by receding glacial ice, and it may become one of many as ancient plant materials are newly uncovered in a changing climate.

Avaliação da estabilidade do parafuso de fixação em implantes de hexágono interno e cone morse / Evaluation of the stability of the screw fi xation in implants of internal hexagon and morse taper

Torque é a força de aperto exercida sobre um parafuso e um dos principais fatores relacionado com o insucesso das próteses implanto suportadas. A falha na união do parafuso podeocorrer tanto por uma pequena quantidade de torque, como por um excesso de torqu e também. Assim,para reduzir o afrouxamento do parafuso deve ser aplicado um torque adequad o, sendo a quantidade de torque realizada de acordo com o tipo de pilar, diâmetro do parafuso e o sistema utilizado. Desta maneira, a proposta dessa pesquisa foi avaliar os sistema de conexão , analisando a força necessária para o destorque de implantes de Hexágono Interno e Cone Morse. Dezoito corpos-de-prova foram divididos em dois grupos: Grupo A – implante de hexágono interno; GrupoB – implante cone Morse. Na seqüência de ensaio, foi aplicado o torque 20 Ncm com um torquímetro mecânico, e após 10 minutos foi realizado um novo torque com o mesmo valor do torque inicial, com o objetivo de reduzir o efeito da sedimentação. Após 2 minutos, foi aplicada uma força em sentido anti-horário com um torquímetro analógico Tohnichi , e mensurado o valor mais alto de força atingido para o destorque. Os resultados foram submetidos a analise de variância e as medias comparadas pelo teste de Mann-Whitney Test em 5% designiˆficância. Observou-se que o valor de destorque foi um valor mediano de 30% do torque inicial aplicado, em ambos os grupos. Não foi constatado diferença estatisticamente signiˆcativa entre os dois grupos. E assim, foi possível concluir que o valor do torque de remoção foi meno r do que otorque inicial aplicado

Torque is a force exerted on a clamping screw and one of principals factors related to the failure of implant-prosthesis. Th e failure of the screw union can occur for a small amount of torque, as by an excess torque also. Th erefore, to reduce loosening of the screw should be a proper torque, the amount of torque being carried out according to the type of abutment, the screw diameter and the system. Th us, the purpose of this study was to evaluate the connection system, analyzing the force required to implant detorque Internal Hexagon and Morse Taper. Twenty specimens were divided into two groups: Group A - internal hexagon implant, Group B - Morse taper implant. Following testing, we applied the initial tightening torque 20 Ncm with a torque wrench mechanic, and aft er 10 minutes was performed a new torque with the same amount of initial torque, in order to reduce the eff ect of sedimentation. Aft er 2 minutes, force was applied in a counter-clockwise with a wrench analog Tohnichi, and measured the highest strength to hit detorque. Th e results were submitted to analysis of variance and the averages compared by Mann-Whit ney Test at 5% signifi cance. It was observed that the value detorque was a median 30% of the initial torque applied in both groups. No statistically signifi cant diff erence was found between the two groups. Th us, it was concluded that the removal torque value was lower than the initial torque applied.

La cola de caballo (Equisetum, Equisetaceae) comercializada y exportada del Perú

Varios productos derivados de plantas se exportan del Perú como suplementos nutricionales, condimentos y otros usos, entre estos últimos tipos se encuentra el helecho “cola de caballo”. Tres nombres se emplean en el comercio: Equisetum arvense, E. bogotense y “E. hiemale”, los cuales no corresponden a las plantas exportadas, las que en cambio son E. giganteum, una especie reconocible por detalles morfológicos en sus ejes, ornamentación y distribución de sus estomas.

Several plant products are exported from Peru as food supplements (nutraceuticals), condiments and other uses for human consumption, among them the horsetail fern. Three names are used in commerce: Equisetum arvense, E. bogotense and “E. hiemale”; none of which represent the species being exported; instead the species in commerce is E. giganteum, easily recognizable by morphological details of their axes, ornamentation and stomata distribution.

Tree-line changes along the Andes: implications of spatial patterns and dynamics.

The Andes provide an extensive latitudinal and topographical framework for studying the factors that control the spatial patterns of forests (timberlines) and their species components expressed through the presence of tree growth forms (tree lines). Despite consistent overall similarities in landscape patterns, many processes must be unique, given the dramatic differences in species richness and biophysical constraints along the Andes. In all cases evaluated to date, morphological plasticity is a common trait of plant species that dominate at tree lines. In fact, many changes observed can be related to species-specific traits. Physiological limitations on tree growth form only explain species limits, while disturbances and cyclical climate fluctuations interact to affect many landscape patterns. Over long periods of time, tree lines provide unique habitats and perhaps opportunities for speciation. Understanding the spatial organization of tree-line dynamics is one viable research approach for evaluating the likely past fluxes and possible future changes.

Abrupt tropical climate change: past and present.

Three lines of evidence for abrupt tropical climate change, both past and present, are presented. First, annually and decadally averaged delta(18)O and net mass-balance histories for the last 400 and 2,000 yr, respectively, demonstrate that the current warming at high elevations in the mid- to low latitudes is unprecedented for at least the last 2 millennia. Second, the continuing retreat of most mid- to low-latitude glaciers, many having persisted for thousands of years, signals a recent and abrupt change in the Earth's climate system. Finally, rooted, soft-bodied wetland plants, now exposed along the margins as the Quelccaya ice cap (Peru) retreats, have been radiocarbon dated and, when coupled with other widespread proxy evidence, provide strong evidence for an abrupt mid-Holocene climate event that marked the transition from early Holocene (pre-5,000-yr-B.P.) conditions to cooler, late Holocene (post-5,000-yr-B.P.) conditions. This abrupt event, approximately 5,200 yr ago, was widespread and spatially coherent through much of the tropics and was coincident with structural changes in several civilizations. These three lines of evidence argue that the present warming and associated glacier retreat are unprecedented in some areas for at least 5,200 yr. The ongoing global-scale, rapid retreat of mountain glaciers is not only contributing to global sea-level rise but also threatening freshwater supplies in many of the world's most populous regions.

Water sorption, solubility, and tensile bond strength of resilient denture lining materials polymerized by different methods after thermal cycling.

STATEMENT OF PROBLEM: The clinical properties of resilient denture lining materials may be influenced by the methods used to polymerize them. PURPOSE: This study evaluated and compared water sorption, solubility, and tensile bond strength of 2 resilient liner materials polymerized by different methods after being thermal cycled. MATERIAL AND METHODS: Two acrylic resin-based resilient liner materials were evaluated: 1 (Light Liner) polymerized by visible light, and 1 (Ever-Soft) processed by 2 different methods: hot water bath and microwave energy. To evaluate water sorption and solubility, 10 disc-shaped specimens (50 x 0.5 mm) were fabricated for each polymerization method, using acetate matrices. The specimens were dried and thermal cycled (2000 cycles) between baths of 5 degrees C and 55 degrees C. After thermal cycling, the specimens were weighed, dried, and weighed again to calculate the water sorption values and solubility. For tensile bond strength assessment, 12 rectangular specimens measuring 83 mm in total length and with a cross-sectional area of 10 x 10 mm were fabricated using each polymerization method. The specimens were also thermal cycled (2000 cycles) and, afterwards, tested in a universal testing machine at a crosshead speed of 6 mm/min with 100 Kg load cell. The type of failure was determined by use of stereoscopic microscopy. The data (for water sorption and solubility, n = 30, and for tensile bond strength, n = 36) were submitted to 1-way analysis of variance. The means were compared using the Bonferroni test (alpha=.05). RESULTS: For water sorption the results showed no significant differences among the polymerization methods. Light Liner showed the lowest solubility values (5.3% +/- 0.3%) when compared to Ever-Soft (hot water bath: 7.3% +/- 1.1% and microwave energy: 7.8 +/- 0.9%). For tensile bond strength, Ever-Soft polymerized by microwave energy (0.7 +/- 0.0 MPa) showed the greatest and most significant ( P <.05) value when compared to Ever-Soft polymerized by hot water bath (0.5 +/- 0.1 MPa) and Light Liner polymerized by visible light (0.5 +/- 0.0 MPa). Most Ever-Soft specimens polymerized by microwave energy and Light Liner specimens showed adhesive/cohesive failures. However, Ever-Soft polymerized by hot water bath showed 50% adhesive/cohesive and 50% adhesive failures. The results at the reline material-resin bond interface showed the absence of cohesive failures. CONCLUSION: Within the limitations of this study, Light Liner showed the lowest solubility values. Ever-Soft should be polymerized by microwave energy to obtain the greatest tensile bond strength values. Materials polymerized by microwave energy and visible light showed predominantly adhesive/cohesive failures.

Tratamento de superfície e cimentação adesiva de cerâmicas aluminizadas: revisão de literatura / Surface treatment and adhesive cementing of glass-infiltrated Alumina ceramic: review of the literature

Nas últimas décadas, as cerâmicas odontológicas, os sistemas adesivos e os agentes cimentantes têm sido estudados, objetivando encontrar novos mecanismos que permitam uma união mais efetiva e duradoura entre os tecidos dentários duros e a restauração indireta. Sabe-se que oprocedimento de preparo para cerâmicas feldspáticas requer o condicionamento da sua superfície com ácido fluorídrico prévio à cimentação. Entretanto, para cerâmicas aluminizadas, em face dassuas características estruturais, o condicionamento ácido não é indicado. Dessa maneira, a escolha do preparo de superfície e do sistema cimentante resinoso torna-se extremamente importante quandose almeja o sucesso do tratamento reabilitador. A presente revisão de literatura teve como objetivo buscar as bases científicas relativas às técnicas alternativas de tratamento superficial e aos agentescimentantes para cerâmicas reforçadas. Para tanto, artigos publicados no período de 1998 a 2007 foram selecionados e analisados, permitindo aos autores concluírem que ainda não há consenso a respeito dos métodos alternativos de tratamento de superfície para os sistemas cerâmicos à base de alumina e da seleção de materiais cimentantes que, usados em conjunto, apresentem resistência de união plenamente satisfatória. Portanto, mais estudos são requeridos a fim de testar e compreenderos mecanismos adesivos responsáveis pela estabilidade das restaurações indiretas a longo prazo.

In the last decades, the dental ceramics, the adhesive systems and luting agents have been studied, objectifying to find new mechanisms that allow to an a more effective and durable bond between the hard tissue dental and indirect restoration. It is known that the procedure ofpreparation for feldspathic ceramics requires the surface conditioning with hydrofluoric acid prior to cementing. Meanwhile alumina ceramics, in face of its structural features, the acid etching is not indicated. In this way, the choice of surface preparation and the resin luting system becomes extremely important when it seeks to successful rehabilitation treatment. The present review of literature had as objective to search cientific bases about alternative techniques of the surfacetreatment and luting agents for high-strength ceramics. For in such a way, articles published in the period 1998 to 2007 had been selected and analyzed, allowing to the authors to conclude that still there is not enough consensus and evidences, regarding the use of alternative methods of surface treatment for the ceramic-based alumina systems and the selection of luting materials that jointly present fully satisfactory strength bond. Therefore, further studies are required in order to test andto understand the responsible adhesive mechanisms by the stability of the indirect restorations in the long term.