A new species of Mollinedia (Monimiaceae, Laurales) from the Quadrilátero Ferrífero, Brazil.

Monimiaceae comprises approximately 26 genera and 250 species, with a pantropical distribution, predominantly occurring in humid forests. In Brazil, it is represented by five genera and 47 species, most of which are found in the Atlantic Forest, particularly in dense ombrophilous forest. Nevertheless, studies on this family in other biomes and vegetation types in Brazil are still scarce. The Quadrilátero Ferrífero (QF), a region located in the state of Minas Gerais, exhibits high plant species richness and endemism. During collections and analysis of herbarium materials from this region, some specimens of Mollinedia caught our attention due to a combination of characteristics that do not match those of any described species within the genus. For this reason, we describe this new taxon and assess its risk of extinction. Additionally, we review the occurrences of Monimiaceae in the QF and provide maps of its geographical distribution. With the description of this new species, the region now hosts eight species of Monimiaceae, two from the genus Macropeplus and six from Mollinedia. The new species is the first endemic species of the Monimiaceae family to be described in the QF. Concerning the extinction risk assessment, the new species was assessed as critically endangered.

ResumoMonimiaceae abrange c. 26 gêneros e 250 espécies, tem distribuição pantropical e suas espécies ocorrem predominantemente em florestas úmidas. No Brasil está representada por cinco gêneros e 47 espécies, a maior parte das quais com ocorrência na Mata Atlântica, em floresta ombrófila densa. Estudos com a família em outros biomas e vegetações ainda são escassos no Brasil. O Quadrilátero Ferrífero (QF), região localizada no estado de Minas Gerais, possui alta riqueza e endemismo de plantas. Durante coletas e análise de materiais herborizados da região, alguns espécimes de Mollinedia nos chamaram a atenção devido a uma combinação de caracteres que não coincidem com nenhuma espécie descrita para o gênero. Este novo táxon é aqui descrito e tem seu risco de extinção avaliado, além disso, revisamos as ocorrências de Monimiaceae no QF, e fornecemos mapas de distribuição geográfica. Com a descrição desta nova espécie, a região apresenta agora oito espécies de Monimiaceae, duas do gênero Macropeplus e seis de Mollinedia. A nova espécie é a primeira da família endêmica do QF. Em relação à avaliação do risco de extinção, a nova espécie foi categorizada como Criticamente em Perigo.

Unraveling the plant diversity of the Amazonian canga through DNA barcoding.

The canga of the Serra dos Carajás, in Eastern Amazon, is home to a unique open plant community, harboring several endemic and rare species. Although a complete flora survey has been recently published, scarce to no genetic information is available for most plant species of the ironstone outcrops of the Serra dos Carajás. In this scenario, DNA barcoding appears as a fast and effective approach to assess the genetic diversity of the Serra dos Carajás flora, considering the growing need for robust biodiversity conservation planning in such an area with industrial mining activities. Thus, after testing eight different DNA barcode markers (matK, rbcL, rpoB, rpoC1, atpF-atpH, psbK-psbI, trnH-psbA, and ITS2), we chose rbcL and ITS2 as the most suitable markers for a broad application in the regional flora. Here we describe DNA barcodes for 1,130 specimens of 538 species, 323 genera, and 115 families of vascular plants from a highly diverse flora in the Amazon basin, with a total of 344 species being barcoded for the first time. In addition, we assessed the potential of using DNA metabarcoding of bulk samples for surveying plant diversity in the canga. Upon achieving the first comprehensive DNA barcoding effort directed to a complete flora in the Brazilian Amazon, we discuss the relevance of our results to guide future conservation measures in the Serra dos Carajás.

Flora of Ferruginous Outcrops Under Climate Change: A Study in the Cangas of Carajás (Eastern Amazon).

Climate change has impacted biodiversity, affecting species and altering their geographical distribution. Besides understanding the impact in the species, it has been advocated that answering if different traits will be differently impacted could allow refined predictions of how climate change will jeopardize biodiversity. Our aim was to evaluate if climate change will potentially impact plant species differently, considering their traits. We evaluated 608 plant species that occur in the naturally open areas of ferruginous outcrops (namely, cangas) in the National Forest of Carajás (Eastern Amazon). Firstly, we estimated the effects of climate change on each species using species distribution modeling, and analyzed this impact in the set containing all species. Secondly, we classified plant species considering the following traits: (i) pollination syndromes (melittophily, phalaenophily, psychophily, cantharophily, entomophily, ornithophily, chiropterophily, anemophily); (ii) habit (tree, shrub, herb, liana, parasite); and (iii) the main habitat of occurrence (open areas and forests). Thirdly, we investigated if the effects of climate change could be significantly more intense considering all the different traits quoted. Our results showed that most plant species will potentially face reduction of suitable habitats under future climate and the scenarios showed that 42% of them may not find suitable areas in the cangas of Carajás. We found no significant difference within each analyzed trait, considering the potential impact of climate change. The most climatically suitable areas (i.e., areas with high probability of species occurrence in the future) are those in the southwest of the study area. These areas can be considered as priority areas for species protection against climate change.

Plastome-based phylogenomics elucidate relationships in rare Isoëtes species groups from the Neotropics.

The genus Isoëtes is globally distributed. Within the Neotropics, Isoëtes occurs in various habitats and ecosystems, making it an interesting case study to address phylogenetic and biogeographic questions. We sequenced and assembled plastomes and ribosomal DNA (rDNA) sequences to reconstruct phylogenetic relationships in Isoëtes from tropical regions in the Neotropics. The ploidy level of nine taxa was established to address the potential source of phylogenetic incongruence in the genus. Node ages were estimated using MCMCTree. The ancestral range estimates were conducted in BioGeoBEARS. Plastome-based phylogenies were congruent throughout distinct matrices and partition schemes, exhibiting high support for almost all nodes. Whereas, we found incongruences between the rDNA and plastome datasets. Chromosome counts identified three diploids, five tetraploids and one likely hexaploid among Neotropical species. Plastome-based node age estimates showed that the radiation of the crown Isoëtes group occurred at 20 Ma, with the diversification of the tropical American (TAA) clade taking place in the Pleistocene at 1.7 Ma. Ancestral range estimates showed that the ancestor of the TAA clade may have evolved first in the dry diagonal area in South America before reaching more humid regions. In addition, the colonization of the Brazilian semiarid region occurred three times, while the occupation of the Cerrado and Amazon regions occurred twice and once, respectively. Our study showed a large unobserved diversity within the genus in warm-dry regions in the Neotropics. Plastomes provided sufficient genomic information to establish a robust phylogenetic framework to answer evolutionary questions in Isoëtes from the Neotropics.

Size and isolation of naturally isolated habitats do not affect plant-bee interactions: A case study of ferruginous outcrops within the eastern Amazon forest.

Pollination may be severely affected by the decreasing size and increasing isolation of habitat patches. However, most studies that have considered the effects of these two variables on plant-pollinator interactions have been carried out in areas that have undergone anthropogenic fragmentation, and little is known about their effects in natural habitats. The Carajás National Forest and Campos Ferruginosos National Park are two protected areas in the eastern Amazon where one can find isolated ferruginous outcrops characterized by iron-rich soil and herbaceous-shrub vegetation surrounded by Amazon forest. These patches of canga provide an opportunity to analyze plant-pollinator interactions in naturally fragmented areas. Our objective was to test whether the size and isolation of naturally isolated outcrops located in Carajás affect plant-pollinator interactions by using pollination syndromes and interaction networks. We determined the pollination syndromes of 771 plant species that occurred in eleven canga patches and performed field work to analyze plant-pollinator networks in nine canga patches. The structure of the plant-pollinator networks was not affected by the size or isolation of the canga patches. Generalist species were present in all canga areas, indicating that they are important in maintaining the plant communities in isolated canga patches. The lack of significance related to the distance between canga patches suggests that the forest does not prevent pollinator movement between canga patches.

Rediscovering two Isoetes species in the Brazilian Amazon and Cerrado after 167 years.

Isoetes amazonica and I. gardneriana were the first two species of the genus to be collected from Brazil. Isoetes amazonica was gathered by Richard Spruce in the Amazon basin near Santarém in the state of Pará in 1850. Isoetes gardneriana was collected by George Gardner in the current Dianópolis in Tocantins State in 1843. Despite being known for a long time by botanists, these species have not been recollected since then, which raised questions about their taxonomic recognition, current distribution ranges and conservation status. Fieldwork efforts led to the rediscovery of I. amazonica and I. gardneriana after 167 years. These collections enrich our understanding of their habitats and morphologies. We provide here re-descriptions for these species. Based on IUCN criteria, Isoetes amazonica and I. gardneriana should be assigned as data deficient (DD) and endangered (EN), respectively. The rediscovery of these species raises hopes that other areas in Amazon and Cerrado biomes harbour I. amazonica and I. gardneriana, respectively. This study will serve as a basis towards the conservation of these species.

Isoetes dubsii and Isoetes santacruzensis, two new species from lowland areas in South America.

Isoetes dubsii sp. nov. and I. santacruzensis sp. nov., two new species from lowland areas in South America, are described, illustrated and compared to similar species. Isoetes dubsii can be distinguished from other species of the Brazilian Pantanal wetlands by a set of characters including leaves that are long, flexuous and trigonal in transverse section, tri-lobate stems, rudimentary velum, pustulate megaspores of 310‒390 µm diameter and laesurae of the megaspore at least four times wider than high. Isoetes santacruzensis has flexuous, filiform leaves, 0.4-0.8 mm wide at mid length and reaching up to 15 cm long, black or reddish-black sporangia, sclerified phyllopodia and sparsely verrucate megaspores of 320‒390 µm in diameter. We also include a key for species from the Brazilian Pantanal wetlands and Bolivia and spore images for all species that are discussed. Isoetes dubsii and I. santacruzensis are only known from their type localities and they may deserve special attention concerning their conservation status. However, based on our current knowledge on these species and according to IUCN Red List criteria, they are assessed here as data deficient (DD).

Plotting a future for Amazonian canga vegetation in a campo rupestre context.

In order to establish effective conservation strategy, drivers of local and regional patterns of biodiversity need to be understood. The composition of local biodiversity is dependent on a number of factors including evolution and redistribution of lineages through dispersal and environmental heterogeneity. Brazilian canga is characterised by a ferrugineous substrate, found both in the Iron Quadrangle of Minas Gerais and in the Carajás mountains in Amazonia. Canga is one of several specialised habitat types comprising Brazilian campo rupestre, a montane vegetation found within or adjacent to several major Brazilian bioregions, including the Atlantic Forest and Amazonia, with exceptionally high levels of diversity and endemism arising from both history of dispersal and environmental variation. In order to inform biodiversity conservation for canga, and more broadly for campo rupestre, we performed floristic and phylogenetic analyses investigating affinities between 28 sites on different substrates (canga and quartzite) and geographic locations (Carajás, Pará [Amazonia]; Cadeia do Espinhaço, Minas Gerais; Chapada Diamantina, Bahia). Through analysis of 11204 occurrences of 4705 species of angiosperms, we found that Amazonian Carajás canga plant communities formed a cohesive group, distinct from species assemblages found in Eastern Brazil (Minas Gerais, Bahia), either on canga or quartzite. The phylogenetic megatree of species across all sites investigated shows associations between certain clades and Amazonian canga, with few shared species between the Amazonian Carajás and Eastern Brazil sites, while the floristic comparison shows high levels of heterogeneity between sites. The need for reserves for Amazonian Carajás canga has been recognized and addressed by the creation of a national park. However, current sampling does not provide sufficient reassurance that the canga areas now benefitting from full legal protection adequately represent the regional canga flora.

Completing the jigsaw: the first record of the female plant of Daphnopsisfilipedunculata (Thymelaeaceae), an endemic species from the Brazilian Amazon.

The results of intensive fieldwork in the National Forest of Carajás (FLONA Carajás) led to the discovery of pistillate plants of Daphnopsisfilipedunculata, an endemic species from the Serra dos Carajás, previously known only from staminate individuals. These newly discovered populations add valuable missing information related to pistillate buds, mature flowers and fruits.

Blind Testing: DNA Barcoding Sheds Light Upon the Identity of Plant Fragments as a Subsidy for Cave Conservation.

Plants living above and around caves represent an important, albeit poorly studied, resource within cave ecosystems. The presence of plant material (root-like structures or rhizothemes, saplings, seeds, and seedlings) correlates positively with the biodiversity of the cave dwelling animals as shown for iron-ore caves in Carajás, Pará, Brazil. Plant material collected in caves has proven to be difficult to identify by traditional botanical methods, thus this research aims to provide a qualitative insight into the taxonomy and morphology of rhizothemes and other plant fragments found in the caves. The identification process used a combination of different molecular markers (ITS2, rbcL, and trnH-psbA) followed by a comparison of the sequences obtained against publicly available databases. The rhizothemes were submitted to micromorphological analysis to ascertain their putative root or stem origin and to compare their anatomy with known patterns found in the plant families or genera recovered through molecular matches. All studied samples were Angiosperms, mostly belonging to subclass Rosideae, within four orders: Malpighiales (Euphorbiaceae, Hypericaceae), Sapindales (Anacardiaceae and Sapindaceae), Myrtales (Myrtaceae), Fabales (Fabaceae), and only two belonging to subclass Asteridae, order Gentianales (Apocynaceae). Some of the samples were matched to generic level, with ITS2 being the best marker to identify the fragments because it shows high degree of sequence variation even at specific level and result reliability. All rhizothemes turned out to be roots, and correspondence was found between the existing literature and the individual anatomical patterns for the families and genera retrieved. DNA barcode has proved to be a useful tool to identify plant fragments found in this challenging environment. However, the existence of well curated, authoritatively named collections with ample biological information has proven to be essential to achieve a reliable identification.

Quillworts from the Amazon: A multidisciplinary populational study on Isoetes serracarajensis and Isoetes cangae.

Isoetes are ancient quillworts members of the only genus of the order Isoetales. The genus is slow evolving but is resilient, and widespread worldwide. Two recently described species occur in the Eastern Brazilian Amazon, Isoetes serracarajensis and Isoetes cangae. They are found in the ironstone grasslands known as Canga. While I. serracarajensis is present mostly in seasonal water bodies, I. cangae is known to occur in a single permanent lake at the South mountain range. In this work, we undertake an extensive morphological, physiological and genetic characterization of both species to establish species boundaries and better understand the morphological and genetic features of these two species. Our results indicate that the morphological differentiation of the species is subtle and requires a quantitative assessment of morphological elements of the megaspore for diagnosis. We did not detect differences in microspore output, but morphological peculiarities may establish a reproductive barrier. Additionally, genetic analysis using DNA barcodes and whole chloroplast genomes indicate that although the plants are genetically very similar both approaches provide diagnostic characters. There was no indication of population structuring I. serracarajensis. These results set the basis for a deeper understanding of the evolution of the Isoetes genus.

Effect of thermocycling to adhesive interface of enamel analyzed by polarized light microscopy / Análise do efeito da termociclagem na interface adesivo do esmalte analisada por microscopia de luz polarizada

Objetivo: A desmineralização menos agressiva do esmalte por sistemas adesivos autocondicionantes resulta em maior descoloração, infiltração marginal e falhas em suas restaurações. Deste modo, este estudo teve como objetivo avaliar a microinfiltração por meio da técnica da infiltração de nitrato de prata e formação de tags na interface esmalte/adesivo. Material e Método: Duzentos fragmentos de esmalte foram divididos aleatoriamente em 10 grupos (n = 10) de acordo com o sistema adesivo (Single Bond Adper Plus- (SB), Clearfil Tri-S Bond- (CF), ou Scotchbond Universal- (SBU)) e a superfície do esmalte (lixada (GE), não lixada- (UE), condicionada com ácido fosfórico 37%- (PHA), ou sem condicionamento): (SB-UE), (SB-GE), (CF-UE), (CFGE), (CF-ue/pha), (CF-ge/pha), (SBU-ue), (SBU-ge), (SBU-ue/pha) e (SBU-ge/pha). Metade das amostras restauradas foram submetidas a 20.000 ciclos térmicos. Quatro fatias de 1,0 mm/amostra foram obtidas para avaliar a formação de tags e infiltração de nitrato de prata. Todas as amostras foram examinadas com microscopia de luz polarizada e a percentagem de infiltração foi quantificada. Resultados: Não foram observadas interações entre os três fatores. O sistema adesivo e envelhecimento exibiram uma interação. Foram encontradas diferenças significativas somente após termociclagem: os grupos SB e SBU condicionados apresentaram menor porcentagem de infiltração comparados aos outros grupos, independente do tipo de esmalte. Quanto à analise qualitativa, o comprimento dos tags após condicionamento ácido foi maior para o GE comparado ao UE, independente do sistema adesivo. Conclusão: A aplicação dos sistemas adesivos na técnica autocondicionante mostrou uma formação de tags significativamente menor comparada à técnica convencional. O condicionamento ácido do esmalte previamente aos sistemas adesivos multi-mode é fundamental para reduzir o grau de infiltração na interface adesiva após envelhecimento.

Objective: The less aggressive demineralization of enamel by self-etching systems results in greater staining, marginal leakage, and failure in their restorations, so this study aimed to assess the silver nitrate infiltration and tag formation of the enamel/adhesive interface. Material and Methods: Two hundred enamel fragments were randomly assigned into 10 groups according to the adhesive system (Single Bond Adper Plus- (SB), Clearfil Tri-S Bond-(CF), or Scotchbond Universal-(SBU)) and enamel surface (ground- (ge), unground-(ue), phosphoric acid etching- (pha), or none) (n=10): (SB-ue), (SB-ge), (CF-ue), (CF-ge), (CF-ue/pha), (CF-ge/pha), (SBU-ue), (SBU-ge), (SBU-ue/pha), and (SBUge/pha). Half of the restored samples were submitted to thermocycling. Four slices of 1.0mm/ sample were obtained to evaluate tag formation and silver nitrate infiltration. All of the specimens were examined with Polarized Light Microscopy, and the percentage of infiltration was quantified. Results: No interactions were found among the three factors. The adhesive and aging exhibited an interaction. Significant differences were found only after thermocycling: the SB and SBU-etched groups had decreased infiltration compared with the other groups. The tag length after etching was higher for ge compared with ue, regardless of the adhesive system. Conclusion: The selfetching techniques resulted in significantly less tag formation compared with the conventional technique. The acid pre-etching of enamel with the multi-mode adhesive was fundamental for reducing the degree of infiltration of the adhesive interface after aging

Avaliação da resistência à flexão e do módulo de elasticidade de diferentes materiais restauradores poliméricos tratados ou não termicamente após a fotoativação / Evaluation of flexural strength and elastic modulus of different restorative polymeric materials with or without heat treatment after photoactivation

Objetivo: Resinas compostas para uso direto têm sido frequentemente usadas pelos profissionais para confecção de restaurações indiretas extensas. O objetivo do presente estudo foi avaliar a resistência à flexão (RF) e o módulo de elasticidade (ME) de diferentes materiais restauradores poliméricos diretos, nos tempos de 30min e 24h sem tratamento térmico (TT); e quando submetidos ou não ao TT, sendo armazenados ou não por 180 dias. Materiais e método: Foram confeccionados 200 corpos de prova divididos nos seguintes grupos de acordo com o material: o ormocer microhíbrido Admira Fusion (ADM), a resina tipo "bulk" nanoparticulada Filtek Bulk Fill (BU), a resina composta convencional nanoparticulada Filtek Z350XT (Z350) e resina composta convencional microhíbrida IPS Empress Direct (EMP). Os grupos foram subdivididos (n=10) nos tempos de 30min sem TT, 24h com e sem TT ou 180 dias com e sem TT. Os corpos de prova (10 mm x 2 mm x 2 mm) foram confeccionados usando-se um molde tripartido de aço inox, no qual o material foi inserido em incremento único e fotoativado por 20s de cada lado. No final do período de 24h da fotoativação, o TT foi realizado por 10min em estufa à temperatura controlada de 170°C. O armazenamento das amostras de 180 dias foi em água destilada em ambiente escuro a 37°C. O teste de resistência à flexão de 3 pontos foi realizado em uma máquina de ensaio Instron à velocidade de 1,0 mm/min. Resultados: Os resultados foram obtidos em MPa (RF) e GPa (ME), sendo depois submetidos à análise estatística ao nível de significância de 5%. Todos materiais tiveram aumentos significativos do tempo de 30min para o tempo de 24h, tanto para a RF quanto para o ME (p<0,05). A realização do TT promoveu aumento nos valores de RF para as resinas compostas BU e EMP no tempo de 24h e Z350 no tempo de 180 dias (p<0,05). Para a BU sem TT, o armazenamento não influenciou nos resultados de RF. A realização do TT promoveu aumento nos valores de ME para o ADM nos dois tempos de análise, e para as resinas compostas EMP, BU e Z350 no tempo de 24h (p<0,05). Houve diminuição significativa no ME de ADM e EMP após 180 dias em comparação ao tempo de 24h, independente do TT e para BU com TT (p<0,05). Não houve diferença quanto ao ME na comparação entre 180 dias e 24h para a BU sem TT e para a Z350 com TT (p>0,05). Conclusões: Pode-se concluir que a influência do tempo de 30min para o tempo de 24h na RF e no ME independe do material. A influência do armazenamento e do TT na RF e no ME são materiais dependentes(AU)

Purpose: Direct composite resins are often used by professionals for making extensive indirect restorations. The aim of this investigation was to evaluate flexural strength and elastic modulus of different restorative polymeric materials at 30 minutes and 24 hours without heat treatment (HT); and with and without HT at 24 hours and 180 days post cure. Materials and method: 200 samples were prepared and divided according to the material as follows: microhybrid ormocer Admira Fusion (ADM), nanofilled bulk-fill composite resin Fitek Bulk Fill (BU), nanofilled universal composite resin Filtek Supreme Ultra (Z350) and microhybrid universal composite resin IPS Empress Direct (EMP). Groups were subdivided (n=10) at 30 minutes into: without HT (30 min), 24 h with and without HT and 180 days with and without HT. The samples (10 mm x 2 mm x 2 mm) were made in a tri-part stainless steel mold where the material was inserted and light-cured for 20 seconds on each side. At the end of the 24 h period HT at 170°C was performed for 10 minutes in a dry heat oven. The 180 day storage samples were placed in destilled water at 37°C in the dark. A standard three point bending test was conducted on all samples with a universal testing machine (Instron) at a crosshead speed of 1.0 mm/min. Results: The results were recorded in MPa (flexural strength) and GPa (elastic modulus) and data were analyzed statistically at a significance level of 5%. All the materials had a significant increase in flexural strength and elastic modulus from 30 minutes to 24 hours (p<0.05). HT promoted an increase in flexural strength for BU and EMP at 24 hours and Z350 at 180 days (p<0,05). Storage didn't influence flexural strength for BU without HT. HT promoted elastic modulus increase for ormocer ADM at both testing times and for EMP, BU and Z350 at 24 hours (p<0.05). With regard to ADM and EMP the elastic modulus decreased significantly after 180 days in comparison to 24 h independent of HT. BU with HT also decreased in modulus after 180 days (p<0.05). There was no significant difference in elastic modulus between 24 hours and 180 days for BU without HT and for Z350 with HT (p>0.05). Conclusions: It can be concluded that the influence of time from 30 minutes to 24 hours in flexural strength and elastic modulus is independent of the material. Storage and HT influence on flexural strength and elastic modulus are material dependent(AU)

Syngonanthus androgynus, a Striking New Species from South America, its Phylogenetic Placement and Implications for Evolution of Bisexuality in Eriocaulaceae.

In the present study, we describe and illustrate a remarkable new species of Syngonanthus from South America (Bolivia, Brazil and Peru). This new species is quickly distinguished from all species in the genus by trimerous and bisexual flowers, a unique set of characteristics in Syngonanthus. Complementary to this study, sequences of 33 species were downloaded from GenBank and four species had sequences newly generated for this study. Molecular phylogenetic analyses based on nuclear ribosomal ITS and the plastid regions psbA-trnH and trnL-F were performed to determine its systematic position. The results have shown S. androgynus closely related to a well-supported clade that has been treated as Syngonanthus sect. Carphocephalus. Floral traits associated with this new plant also were surveyed. Character reconstruction suggests that the bisexual flowers originated independently more than once in the genus. However, trimerous flowers appear to be an ancestral condition of the whole genus.

Influence of crown ferrule heights and dowel material selection on the mechanical behavior of root-filled teeth: a finite element analysis.

PURPOSE: This study used the 3D finite element (FE) method to evaluate the mechanical behavior of a maxillary central incisor with three types of dowels with variable heights of the remaining crown structure, namely 0, 1, and 2 mm. MATERIALS AND METHODS: Based on computed microtomography, nine models of a maxillary central incisor restored with complete ceramic crowns were obtained, with three ferrule heights (0, 1, and 2 mm) and three types of dowels (glass fiber = GFD; nickel-chromium = NiCr; gold alloy = Au), as follows: GFD0--restored with GFD with absence (0 mm) of ferrule; GFD1--similar, with 1 mm ferrule; GFD2--glass fiber with 2 mm ferrule; NiCr0--restored with NiCr alloy dowel with absence (0 mm) of ferrule; NiCr1--similar, with 1 mm ferrule; NiCr2--similar, with 2 mm ferrule; Au0--restored with Au alloy dowel with absence (0 mm) of ferrule; Au1--similar, with 1 mm ferrule; Au2--similar, with 2 mm ferrule. A 180 N distributed load was applied to the lingual aspect of the tooth, at 45° to the tooth long axis. The surface of the periodontal ligament was fixed in the three axes (x = y = z = 0). The maximum principal stress (σ(max)), minimum principal stress (σ(min)), equivalent von Mises (σ(vM)) stress, and shear stress (σ(shear)) were calculated for the remaining crown dentin, root dentin, and dowels using the FE software. RESULTS: The σ(max) (MPa) in the crown dentin were: GFD0 = 117; NiCr0 = 30; Au0 = 64; GFD1 = 113; NiCr1 = 102; Au1 = 84; GFD2 = 102; NiCr2 = 260; Au2 = 266. The σ(max) (MPa) in the root dentin were: GFD0 = 159; NiCr0 = 151; Au0 = 158; GFD1 = 92; NiCr1 = 60; Au1 = 67; GFD2 = 97; NiCr2 = 87; Au2 = 109. CONCLUSION: The maximum stress was found for the NiCr dowel, followed by the Au dowel and GFD; teeth without ferrule are more susceptible to the occurrence of fractures in the apical root third.

Recovering the function and esthetics of fractured teeth using several restorative cosmetic approaches. Three clinical cases.

The teeth most commonly affected by trauma are the maxillary central incisors. The most frequent types of traumatic dental injuries to permanent teeth are enamel fractures, enamel and dentine fractures, and enamel and dentine fractures with pulp involvement. This article describes three clinical cases with different levels of traumatized maxillary incisors and several cosmetic approaches for recovery of the esthetics and the masticatory function, as well as the social/psychological aspects of treatment. All cases involved young adult men. The three clinical cases involve dentin and enamel fractures, dentin and enamel fractures with pulp exposure, and dentin and enamel fractures with pulp exposure associated with root fracture. The cosmetic treatments used to resolve fractures were direct composite resin by layering technique, indirect all-ceramic restorations (laminate veneer and ceramic crowns over the teeth), and immediate implant after extraction followed by immediate loading (ceramic abutments with ceramic crown over implant). In all three cases, excellent functional and esthetic results were achieved by use of these treatment modalities. The patients were very satisfied with the results.

Integrando forma à função no fechamento de diastemas / Integration between function and form in diastema closure

Mesmo sendo o fechamento de diastemas comumente realizado, esse procedimento apresenta desafios aos profissionais que o executam. O estabelecimento de um perfil de emergência e ponto de contato adequados nos dentes restaurados é fundamental para evitar resultados como forma artificial, ausência de ponto de contato, permanência de espaço negro interproximal ou mesmo sobre contorno nas imediações do tecido gengival. Este caso clínico descreve uma técnica para fechamento de diastemas, em que especial cuidado é tomado para criar um resultado estético-funcional adequado.

Even being the diastemas closing a commonly realized procedures, challenging are presents. The restoration of the inter-proximal contact and the gingival shape is fundamental to avoid artificial anatomy, non-presence of the inter proximal contact, permanence oh black spaces or over shape of restoration. The clinical case demonstrates a precise technique to close diastemas, whose special attention is given to create a function-aesthetical results.

Incisivo lateral superior

[Explica o que é o incisivo lateral superior e que são frequentes as variações de formas anatômicas e cita as mais comuns baseado nos autores citados. Apresenta uma sequência de enceramento progressivo de um incisivo lateral superior direito, realizado com ceras de diversas cores e translucidez.]