Nature-mimicking layering with composite resins through a bio-inspired analysis: 25 years of the polychromatic technique.

OBJECTIVES: For decades, the dental community has discussed which materials would be the ideal substitutes for lost tooth structure. Initially, the biomimetic approach advocated that feldspathic ceramics would be the material of choice for enamel. However, given the complexity of obtaining excellent dental technicians and the financial cost, are composite resins a suitable replacement? The optical properties with opalescence and fluorescence effects, as well as this material's high fracture toughness, indicate it as a long-lasting restorative material. However, because this material depends on the operator's expertise, knowledge of layering techniques and the selection of each material for the different layers is required. Thus, knowledge of the polychromatic technique through a bioinspired approach is necessary to obtain results of life-like restorations. This article aims to review the polychromatic layering technique (PLT), considering the optical and mechanical properties of dentin and enamel and correlating these properties with current composite resins to guide clinicians in selecting the most suitable restoratives for their clinical challenges. CLINICAL CONSIDERATIONS: The polychromatic layering technique is revisited, cross-referencing the properties of dentin and enamel with current composite resin restoratives and their biomimetic properties. The effectiveness and predictability of the PLT are corroborated in clinical cases of varying degrees of difficulty requiring different layering strategies. CONCLUSION: After the bio-inspired analysis, using nature as a model to be understood and followed, it is possible to note how the polychromatic technique remains current and viable in mimicking nature, providing esthetic and natural results in the layering of composite resins. CLINICAL SIGNIFICANCE: Composite resins effectively replicate the optical and mechanical characteristics of natural dentin and enamel through the bioinspired approach presented by the polychromatic layering technique.

Masking ability of resin composites: Effect of the layering strategy and substrate color.

OBJECTIVE: To evaluate the effect of layering strategy and substrate color on the masking ability of resin composites. MATERIALS AND METHODS: A1-shaded specimens from Charisma Diamond and Filtek Z350XT were produced using different layering strategies. Color measurements were made by a reflectance spectrophotometer over A2, C2, A3.5, C3, C4 substrates. Color differences were calculated and interpreted by the 50%:50% perceptibility and acceptability visual thresholds. Data was analyzed by Kruskal-Wallis and Dunn post hoc test. Chi-square test was used to determine the association between masking ability, and independent variables. RESULTS: Color differences were significantly lower on A2 and C2 in comparison with C4 for the majority of the layering strategies. Acceptable matches were observed on most of the combinations over A2. Moderately unacceptable mismatches were observed in most of the combinations over C2 and A3.5. Clearly unacceptable mismatches were observed on the C3 and C4. The ΔE00 color shifts were predominantly influenced by ΔL00 for all layering strategies and substrate colors. CONCLUSION: Masking ability was affected by the layering strategy and substrate color. Acceptable masking was associated with A2 and C2, and with layering strategy composed of 0.5 mm enamel opacity and 1.0 mm dentin opacity thicknesses, using the Filtek Z350XT. CLINICAL SIGNIFICANCE: Resin composites-shade A1-applied by different layering strategies with a final thickness of 1.5 mm were able to mask mild and moderately discolored substrates. Severely discolored substrates were not masked effectively.

A novel fast-vegetative propagation technique of the pioneer shrub Baccharis linearis on mine tailings by adding compost.

Interest in Baccharis linearis has increased as an alternative for assisted phytostabilization due to its spontaneous colonization of tailings dumps. The search for a novel fast-vegetative propagation technique to accelerate its coverage on mine tailings is a promising research area for sustainable mine closure plans. In this study, we determined the optimal proportion of compost and tailings as growing media to promote fast B. linearis propagation through a compound layering technique. The assessed growing substrates were: 100% tailings, 70% tailings + 30% compost, and 50% tailings + 50% compost. After 84 days of growth, the change in number and height of layering branches, root and shoot dry mass, percentage of ground coverage, and substrate chemical properties were assessed. The main results showed that compound layering of B. linearis is possible with compost addition. The growth of new roots and layering branches was significantly improved by either 30% or 50% compost addition into tailings, due to chemical improvements of substrate (higher nutrients and pH and decreased copper bioavailability). The study confirms that the compound layering of B. linearis may be an effective and novel technique for speeding the reclamation of post-operative mine tailings, which is improved by the incorporation of compost.

Composite veneers: The direct-indirect technique revisited.

OBJECTIVE: This article provides an update on the direct-indirect composite veneer technique. CLINICAL CONSIDERATIONS: Composite veneers have long been used as a conservative and esthetic treatment option for anterior teeth. While they are generally performed using a direct technique, there has been renewed interest in the direct-indirect composite veneer technique because of its advantages and broad indications for restoration of tooth color and morphology. In the direct-indirect composite veneer technique, the selected composites are initially applied on the tooth using a layering approach, without any bonding agent, sculpted to a primary anatomic form with slight excess, and light-cured. The partially polymerized veneer is then removed from the tooth, heat-tempered, and finished to final anatomy and processed extra-orally before being luted. Advantages of this technique include enhanced physical and mechanical properties afforded by the tempering process, unrivaled marginal adaptation, enhanced finishing and polishing, and the ability to try-in the veneer before luting, enabling a shade verification and modulation process that is not possible with the direct technique. The direct-indirect approach also affords enhanced gingival health and patient comfort. CONCLUSION: This article reviews the direct-indirect composite veneer technique, and outlines critical steps and tips for clinical success. CLINICAL SIGNIFICANCE: The direct-indirect technique for composite veneers combines advantages of the direct composite placement technique with those of the indirect veneer technique, including operator control, single-visit fabrication and delivery, increased material properties, and excellent esthetics.

Clinical Performance of Direct Anterior Composite Restorations Using Esthetic Dual-Shade versus Polychromatic Natural Layering Technique: a split mouth randomized controlled clinical tria / Avaliação clínica do comportamento de desgaste do esmalte humano e lascamento da zircônia de cobrimento contra a zircônia monolítica (ensaio clínico randomizado controlado)

Objective: to evaluate the clinical performance of the dual shade layering and polychromatic resin composite layering techniques using a randomized controlled trail. Material and Methods: 42 participants (84 restorations) of class IV or class III through and through within a pair of anterior contra-lateral teeth were randomly allocated into two groups according to technique of composite restoration placement: control "polychromatic layering" and intervention "dual-shade layering". Follow-up was done at 1 month (baseline) and 1 year. Restorations were evaluated using Visual Analog Scale (VAS), restoration color shade match using Vita Easyshade V ®, and blinded assessor using FDI criteria for assessment of dental restorations measuring (aesthetic properties). Chi-square test was used to compare between restorations of both techniques. Results: There was no statistically significant difference between restorations of both techniques for patient satisfaction outcome, restorations color match outcome, and for all tested FDI outcomes except surface luster with 100% success. Conclusion: Bothdual-shade layering and polychromatic natural layering techniques, exhibited acceptable clinical and esthetic performance (AU)

Objetivo: Avaliar o comportamento de desgaste do esmalte humano e lascamento de zircônia de cobrimento e monolítica para restaurações posteriores de cobertura total. Material e métodos: Trinta e quatro restaurações de zircônia de cobertura total (dezessete em cada grupo) foram fabricadas. Os pacientes foram divididos em dois grupos de acordo com o tipo de zircônia utilizada; grupo 1 (grupo comparador) coroas com zircônia de cobrimento e grupo 2 (grupo de intervenção) coroas únicas de zircônia monolítica. Todas as coroas foram fabricadas e polidas em laboratório. Para medidas de desgaste de dentes opostos, foi utilizado um perfilômetro 3D sem contato, onde réplicas de resina epóxi foram construídas para o arco oposto imediatamente após a cimentação das coroas, três, seis e doze meses. O lascamento da restauração foi medido usando critérios modificados dos Serviços de Saúde Pública dos Estados Unidos (USPHS). Resultados: Todas as restaurações foram relatadas como alfa sem lascamento. Não houve diferença estatisticamente significativa entre (Grupo 1) e (Grupo 2) para o teste de desgaste. Conclusão: As restaurações monolíticas e de cobrimento revelaram propriedades mecânicas satisfatórias sem lascamento após um ano de uso clínico. O desgaste do esmalte oposto foi clinicamente aceitável para ambos os materiais (AU)

Respiração basal e relação de estratificação em solo cultivado com citros e tratado com resíduos orgânicos no estado de Sergipe / Basal respiration and stratification ratio in soil cultivated with citrus and treated with organic residues in the state of Sergipe

A utilização de resíduos orgânicos no solo para melhorar sua qualidade, fornecer nutrientes as plantas e aumentar o estoque de carbono é uma prática antiga, mas pouco é conhecido sobre a aplicação de compostagem laminar em pomares de citros. O objetivo do presente trabalho foi avaliar a atividade microbiana, através da respiração basal, e as diferentes taxas de estratificação de algumas variáveis relacionadas a esse atributo, em um Argissolo Vermelho Amarelo tratado com resíduos orgânicos e cultivado com citros, no estado de Sergipe. Foram coletadas amostras de solo em três profundidades (0-5, 5-10 e 10-15 cm) em área cultivada com laranja pêra (Citrus sinensis, L. Osbeck) sob diferentes tratamentos 1.Compostagem laminar (aplicação, na projeção da copa, na zona de coroamento da planta, de camadas alternadas de resíduos orgânicos frescos e esterco ovino) 2. Compostagem laminar + NPK (o mesmo descrito no item 1 + adubação NPK recomendada pela análise do solo); 3. Húmus (aplicação, na projeção da copa, de composto organico humificado); 4. Húmus + NPK (o mesmo descrito no item 3 + NPK; 5. Controle + NPK (manejo convencional, onde a projeção da copa é mantida livre de plantas invasoras através de capina manual; com aplicação de fertilizantes aplicado na projeção da copa); 6. Controle sem NPK (o mesmo descrito no item 5, sem aplicação de fertilizantes). O estudo foi realizado com...(AU)

The use of organic residues in the soil to improve its quality, provide nutrients to plant growth and increase carbon storage is an ancient practice, but little is known about the application of laminar composting in citrus orchards. The objective of this study was to evaluate the microbial activity through microbial respiration, and the different rates stratification of some variables related to this attribute of an Ultisol cultivated with citrus and treated with organic waste in the state of Sergipe. Soil samples were collected in the layers 0-5 cm, 5-10 cm, and 10-15 cm in a citrus orchard (Citrus sinensis, L. Osbeck) under different treatments 1. Layering organic residue (crop wastes placed in layers under the plant canopy) 2. Layering organic residue + NPK (the same as described in iten 1 + NPK); 3. Humus (Humified organic compost applied under the plant canopy); 4. Humus + NPK (the same as described in iten 3 + NPK); 5. Control + NPK (plant canopy was kept free of residues, + NPK application); 6. Control NPK (plant canopy was kept free of residues, without application of NPK), with three replications. It has been found that the use of the organic residue in the plant canopy increased microbial respiration rate and total organic matter content, as well as an increase in some chemical attributes as pH, P, Ca and Mg in all treatments compared the control. The ratio...(AU)

Respiração basal e relação de estratificação em solo cultivado com citros e tratado com resíduos orgânicos no estado de Sergipe / Basal respiration and stratification ratio in soil cultivated with citrus and treated with organic residues in the state of Sergipe

A utilização de resíduos orgânicos no solo para melhorar sua qualidade, fornecer nutrientes as plantas e aumentar o estoque de carbono é uma prática antiga, mas pouco é conhecido sobre a aplicação de compostagem laminar em pomares de citros. O objetivo do presente trabalho foi avaliar a atividade microbiana, através da respiração basal, e as diferentes taxas de estratificação de algumas variáveis relacionadas a esse atributo, em um Argissolo Vermelho Amarelo tratado com resíduos orgânicos e cultivado com citros, no estado de Sergipe. Foram coletadas amostras de solo em três profundidades (0-5, 5-10 e 10-15 cm) em área cultivada com laranja pêra (Citrus sinensis, L. Osbeck) sob diferentes tratamentos 1.Compostagem laminar (aplicação, na projeção da copa, na zona de coroamento da planta, de camadas alternadas de resíduos orgânicos frescos e esterco ovino) 2. Compostagem laminar + NPK (o mesmo descrito no item 1 + adubação NPK recomendada pela análise do solo); 3. Húmus (aplicação, na projeção da copa, de composto organico humificado); 4. Húmus + NPK (o mesmo descrito no item 3 + NPK; 5. Controle + NPK (manejo convencional, onde a projeção da copa é mantida livre de plantas invasoras através de capina manual; com aplicação de fertilizantes aplicado na projeção da copa); 6. Controle sem NPK (o mesmo descrito no item 5, sem aplicação de fertilizantes). O estudo foi realizado com...

The use of organic residues in the soil to improve its quality, provide nutrients to plant growth and increase carbon storage is an ancient practice, but little is known about the application of laminar composting in citrus orchards. The objective of this study was to evaluate the microbial activity through microbial respiration, and the different rates stratification of some variables related to this attribute of an Ultisol cultivated with citrus and treated with organic waste in the state of Sergipe. Soil samples were collected in the layers 0-5 cm, 5-10 cm, and 10-15 cm in a citrus orchard (Citrus sinensis, L. Osbeck) under different treatments 1. Layering organic residue (crop wastes placed in layers under the plant canopy) 2. Layering organic residue + NPK (the same as described in iten 1 + NPK); 3. Humus (Humified organic compost applied under the plant canopy); 4. Humus + NPK (the same as described in iten 3 + NPK); 5. Control + NPK (plant canopy was kept free of residues, + NPK application); 6. Control NPK (plant canopy was kept free of residues, without application of NPK), with three replications. It has been found that the use of the organic residue in the plant canopy increased microbial respiration rate and total organic matter content, as well as an increase in some chemical attributes as pH, P, Ca and Mg in all treatments compared the control. The ratio...

Propagação vegetativa de jambeiro vermelho [Syzygium malaccense (L.) Merr. & L.M. Perry] / Vegetative propagation of malay apple [Syzygium malaccense (L.) Merr. & L.M. Perry]

O jambeiro vermelho [Syzygium malaccense (L.) Merr. & L.M. Perry] se apresenta como opção ao fruticultor por apresentar frutos atrativos e bem aceitos pelo consumidor. A dificuldade de cultivo dessa espécie reside no fato de que a planta possui um porte demasiadamente alto e longo período juvenil quando propagada por semente, com isso, é desejável sua multiplicação vegetativa visando a antecipar o período produtivo e diminuir seu porte. Foi estudada a possibilidade de clonagem dessa espécie pelas técnicas de estaquia, alporquia e enxertia. No experimento por estaquia, testaram-se três doses de ácido indolbutírico (AIB) (0, 1.000 3.000 e 5.000 mg L-1) em dois comprimentos de estacas herbáceas (15 e 25 cm). No experimento de alporquia, avaliaram-se duas épocas de realização do alporque (verão e outono) e quatro doses de AIB (0, 1.000, 4.000, 7.000 e 10.000 mg kg-1). Na enxertia, analisou-se a compatibilidade do jambeiro vermelho (S. malaccense) sobre o jambeiro rosa [Syzygium jambos (L.) Alston] com dois diâmetros de porta-enxertos (0,5 e 0,8 cm) em duas épocas (inverno e verão), pelo método de enxertia de topo em fenda cheia. A estaquia obteve até 20 por cento de enraizamento, independentemente da dose de AIB, exceto na dose de 5.000 mg L-1, que apresentou efeito negativo ao enraizamento entre estacas de 15 cm; não houve sucesso para alporquia e enxertia, nas condições estudadas.

The Malay Apple [Syzygium malaccense (L.) Merr. & L.M. Perry] is an option for the producer as its fruits are attractive and well accepted by the consumer. The difficulty of culture of this species is that the plant is very tall and has a long juvenile period when propagated by seed, making its vegetative propagation necessary to anticipate the productive period and decrease its size. The possibility of vegetative propagation of this species was studied by cutting, layering, and grafting. In the cutting experiment, three doses of indolbutyric acid (IBA) (0, 1,000, 3,000, and 5,000 mg L-1) were tested in two lengths of herbaceous cuttings (15 and 25 cm). In the layering experiment, two periods of layering (summer and autumn) and four doses of IBA (0, 1,000, 4,000, 7,000, and 10,000 mg kg-1) were evaluated. For grafting, the compatibility between S. malaccense and S. jambos (L.) Alston as rootstock was studied with two diameters (0.5 and 0.8 cm) and in two periods (winter and summer), by method of full graft. For cuttings, the percentage of rooting was 20 percent, independently of the IBA doses, except for 5,000 mg L-1 that showed negative effect on 15 cm cuttings; layering and grafting were not successful in the studied conditions.

Development and in vitro evaluation of sustained release multiparticulate tablet of freely water soluble drug / Desenvolvimento e avaliação in vitro de liberação sustentada de comprimido multi partículas livre de drogas solúveis em água

Blends of aqueous dispersion of a hydrophobic and hydrophilic polymer, namely Surelease®: hydroxypropyl methylcellulose (Surelease®: HPMC E15) were used as coating materials to control the drug release from coated pellets of the highly water soluble drug metoprolol succinate. Varying the polymer blends, ranges of drug release patterns were obtained at pH 6.8. The present study dealt with diffusion of drug through plasticized Surelease®/ hydroxypropyl methylcellulose (HPMC E15) films prepared by coating of drug and polymers onto non-pareil seeds using the solution layering technique. The release of metoprolol succinate from coated pellets was decreased with increased coating load of polymer. The optimized formulation was obtained by 3² full factorial design. The release profile revealed that the optimized formulation follows zero order release kinetics. The stability data showed no interaction for storage at 25ºC and 60 percent relative humidity.

Misturas das dispersões aquosas de polímero hidrofóbico e de polímero hidrofílico, a saber, Surelease®: hidroxipropil metilcelulose (Surelease®: HPMC E15), foram utilizadas como material de revestimento para controlar a liberação de fármacos de péletes revestidos de fármaco altamente solúvel, o succinato de metoprolol. Variando as misturas de polímeros, obtiveram-se faixas de padrão de liberação do fármaco em pH 6,8. O presente estudo tratou da difusão do fármaco através de filmes de Surelease®/hidroxipropil metilcelulose(HPMC E15), preparados pelo revestimento do fármaco e dos polímeros em sementes nonpareil, utilizando técnica de solução em camada. A liberação de succinato de metoprolol dos péletes revestidos diminuiu com o aumento da carga de polímero de revestimento. A formulação otimizada foi obtida por planejamento fatorial 3². O perfil de liberação revelou que a formulação otimizada segue a cinética de liberação de ordem zero. Os dados de estabilidade mostraram não haver interação por armazenamento a 25 ºC e umidade relativa de 60 por cento.

ASPECTOS ANATÔMICOS DO ENRAIZAMENTO DA VIDEIRA MUSCADÍNIA (Vitis rotundifolia Michx.) ATRAVÉS DE ALPORQUIA

The propagation of grapes is ordinarily carried out by vegetative methods like cuttings and graftings, which not always present satisfactory results, especially for those species with low rooting ability, endangering the commercial production. The muscadine grape (Vitis rotundifolia Michx.) is considered recalcitrant for rooting. Its propagation by cuttings shows that growth regulators have few or no benefits on rooting. Nowadays, air-layering is reported as a propagation method that promotes good rooting when combined with the application of growth regulators. This work aimed to evaluate the efficiency of air-layering process in relation to muscadine grape rooting, as well as to study the callus and the adventitious root anatomy. The results showed that the practice of ringing is more successfull than the bark retreating for rooting. The addition of naphtalene acetic acid did not affect significantly the rooting. The adventitious roots appeard close to the cambial area at the node and internode branch regions. There was no root formation from callus tissue. Its tissue was characterized by meristematic activity and absence of starch.

A multiplicação das videiras é comumente realizada através de processos vegetativos como a estaquia e a enxertia, os quais nem sempre apresentam resultados satisfatórios, especialmente para as espécies de difícil enraizamento, comprometendo a produção comercial. A uva muscadínia (Vitis rotundifolia Michx.) é considerada uma planta difícil de enraizar. Sua propagação através da estaquia mostra que o emprego de reguladores vegetais proporciona pouco ou nenhum benefício ao enraizamento das estacas. Atualmente, a alporquia em frutíferas vem se apresentando como um método de propagação que proporciona um bom enraizamento, aliado à aplicação de reguladores vegetais. Este trabalho procurou avaliar a eficiência do processo de alporquia com relação ao enraizamento da uva muscadínia bem como estudar a anatomia dos calos e das raízes adventícias. Pode-se concluir que a prática do anelamento mostra-se mais efetiva em proporcionar o enraizamento do que a retirada de lascas. A adição de ácido naftalenacético não afetou significativamente o enraizamento. As raízes adventícias apareceram nas proximidades da região cambial, nas regiões nodais e internodais dos ramos. Não ocorreu a formação de raízes diretamente do calo. O tecido do calo caracterizou-se por ser meristematicamente ativo e não apresentar amido.

ASPECTOS ANATÔMICOS DO ENRAIZAMENTO DA VIDEIRA MUSCADÍNIA (Vitis rotundifolia Michx.) ATRAVÉS DE ALPORQUIA

The propagation of grapes is ordinarily carried out by vegetative methods like cuttings and graftings, which not always present satisfactory results, especially for those species with low rooting ability, endangering the commercial production. The muscadine grape (Vitis rotundifolia Michx.) is considered recalcitrant for rooting. Its propagation by cuttings shows that growth regulators have few or no benefits on rooting. Nowadays, air-layering is reported as a propagation method that promotes good rooting when combined with the application of growth regulators. This work aimed to evaluate the efficiency of air-layering process in relation to muscadine grape rooting, as well as to study the callus and the adventitious root anatomy. The results showed that the practice of ringing is more successfull than the bark retreating for rooting. The addition of naphtalene acetic acid did not affect significantly the rooting. The adventitious roots appeard close to the cambial area at the node and internode branch regions. There was no root formation from callus tissue. Its tissue was characterized by meristematic activity and absence of starch.

A multiplicação das videiras é comumente realizada através de processos vegetativos como a estaquia e a enxertia, os quais nem sempre apresentam resultados satisfatórios, especialmente para as espécies de difícil enraizamento, comprometendo a produção comercial. A uva muscadínia (Vitis rotundifolia Michx.) é considerada uma planta difícil de enraizar. Sua propagação através da estaquia mostra que o emprego de reguladores vegetais proporciona pouco ou nenhum benefício ao enraizamento das estacas. Atualmente, a alporquia em frutíferas vem se apresentando como um método de propagação que proporciona um bom enraizamento, aliado à aplicação de reguladores vegetais. Este trabalho procurou avaliar a eficiência do processo de alporquia com relação ao enraizamento da uva muscadínia bem como estudar a anatomia dos calos e das raízes adventícias. Pode-se concluir que a prática do anelamento mostra-se mais efetiva em proporcionar o enraizamento do que a retirada de lascas. A adição de ácido naftalenacético não afetou significativamente o enraizamento. As raízes adventícias apareceram nas proximidades da região cambial, nas regiões nodais e internodais dos ramos. Não ocorreu a formação de raízes diretamente do calo. O tecido do calo caracterizou-se por ser meristematicamente ativo e não apresentar amido.