Preclinical Trial of Ocotea puberula (Rich.) Nees ("Canela-Guaicá") in Wound Healing: Validation of a Traditional Medicine Practice Used by Indigenous Groups in Southern Brazil.

Background: "Canela-guaicá," "guaicá," or "canela-sebo" [Ocotea puberula (Rich.) Nees] is a native species that is traditionally used by Kaingang indigenous groups for wound healing in southern Brazil. The aim of this study was to extract the mucilage from O. puberula barks, perform its phytochemical and physicochemical characterization, and investigate its healing potential. Methods: A murine wound model was used as a preclinical trial for authentication of the traditional knowledge from Kaingang indigenous communities. Results: Alkaloids and polysaccharides were identified by usual qualitative reactions and Fourier-transform infrared spectroscopy. This natural product showed thermal stability and pseudoplastic properties that were considered suitable for the intended use. A higher initial exacerbation of inflammatory response after 7 days, an improved angiogenesis after 14 days, and an increased wound shrinkage after 21 days were statistically significant for the "canela-guaicá" bark extract in the preclinical trial when compared to the silver calcium alginate dressing (positive control). Conclusion: The healing potential of the "canela-guaicá" bark extract, traditionally used by the Kaingang indigenous community from southern Brazil, was preclinically validated. This study paves the way for designing novel wound dressings containing this natural product in order to treat acute and chronic wounds.

Effect of the Bis-Dimethylamino Benzydrol Coinitiator on the Mechanical and Biological Properties of a Composite.

To examine the effect of the alternative coinitiator 4,4'bis dimethylamino benzydrol (BZN) in degree of conversion (DC), mechanical and biological properties of experimental composites. The coinitiator BZN was used in three concentrations (0.2, 0.5 and 1.2%), and the coinitiator DMAEMA was used as control at the same concentrations as above. The molar concentration of camphorquinone (CQ) and coinitiators was kept constant (1:1). The composites were manipulated and submitted to microhardness test (VHN), flexural and compressive strength (in MPa), elastic modulus (GPa), DC (FT-IR) and in vitro cytotoxicity (against 3T3 fibroblastic cells) of the experimental resins. Data were subjected to two-way ANOVA and Tukey post-test (α=0.05). The experimental composite resin with BZN showed higher DC values compared to control DMAEMA groups. For the mechanical properties, microhardness values were higher in BZN groups; flexural strength and elastic modulus were similar between all the groups. Compressive strength for groups BZN0.5 and DMAEMA0.5 were not statistically different, being the lowest values attributed to group BZN0.2. The experimental resins with BZN and DMAEMA were considered nontoxic against 3T3 fibroblasts. The inclusion of the coinitiator BZN in experimental composites was considered nontoxic against 3T3 fibroblast cells, without compromising DC and mechanical properties.

Effect of the Bis-Dimethylamino Benzydrol Coinitiator on the Mechanical and Biological Properties of a Composite

Abstract To examine the effect of the alternative coinitiator 4,4'bis dimethylamino benzydrol (BZN) in degree of conversion (DC), mechanical and biological properties of experimental composites. The coinitiator BZN was used in three concentrations (0.2, 0.5 and 1.2%), and the coinitiator DMAEMA was used as control at the same concentrations as above. The molar concentration of camphorquinone (CQ) and coinitiators was kept constant (1:1). The composites were manipulated and submitted to microhardness test (VHN), flexural and compressive strength (in MPa), elastic modulus (GPa), DC (FT-IR) and in vitro cytotoxicity (against 3T3 fibroblastic cells) of the experimental resins. Data were subjected to two-way ANOVA and Tukey post-test (α=0.05). The experimental composite resin with BZN showed higher DC values compared to control DMAEMA groups. For the mechanical properties, microhardness values were higher in BZN groups; flexural strength and elastic modulus were similar between all the groups. Compressive strength for groups BZN0.5 and DMAEMA0.5 were not statistically different, being the lowest values attributed to group BZN0.2. The experimental resins with BZN and DMAEMA were considered nontoxic against 3T3 fibroblasts. The inclusion of the coinitiator BZN in experimental composites was considered nontoxic against 3T3 fibroblast cells, without compromising DC and mechanical properties.

Resumo Analisar o efeito do co-iniciador alternativo 4,4'bisdimetilaminobenzidrol (BZN) no grau de conversão (GC) e nas propriedades mecânicas e biológicas de resinas compostas experimentais. O co-iniciador BZN foi utilizado em três concentrações (0,2, 0,5 e 1,2), e o co-iniciador DMAEMA como controle, nas mesmas concentrações acima. A concentração molar entre canforoquinona (CQ) e os co-iniciadores foi mantida constante (1:1). As resinas compostas foram manipuladas e submetidas aos testes de microdureza (VHN), resistência à compressão e flexural (em MPa), módulo de elasticidade (em GPa), GC (em %, por meio de espectroscopia micro-Raman e FTIR com KBr), citotoxicidade in vitro (frente às células fibroblásticas 3T3) das resinas experimentais. Os resultados foram submetidos ao teste ANOVA 1 fator e pós-teste de Tukey (α=0,05). As resinas compostas experimentais com o BZN apresentaram GC e propriedades mecânicas satisfatórias, além de serem consideradas atóxicas a fibroblastos 3T3. A inclusão do co-iniciador BZN à resina composta foi considerada não tóxica frente a células fibroblásticas 3T3 e sem comprometer o grau de conversão e as propriedades mecânicas da mesma.

Characterisation of Cassava Bagasse and Composites Prepared by Blending with Low-Density Polyethylene

The main objective of this study was to characterise the cassava bagasse and to evaluate its addition in composites. Two cassava bagasse samples were characterised using physicochemical, thermal and microscopic techniques, and by obtaining their spectra in the mid-infrared region and analysing them by using x-ray diffraction. Utilising sorption isotherms, it was possible to establish the acceptable conditions of temperature and relative humidity for the storage of the cassava bagasse. The incorporation of cassava bagasse in a low-density polyethylene (LDP) matrix was positive, increasing the elasticity modulus values from 131.90 for LDP to 186.2 for 70% LDP with 30% SP bagasse. These results were encouraging because cassava bagasse could serve as a structural reinforcement, as well as having environmental advantages for its application in packaging, construction and automotive parts.

Alternative coinitiators applicable to photocurable resin composites.

This review aimed to examine the evolution of the composite resins`s photoinitiator system, with emphasis on those developed in recent years. This review covered literature from 1990 to 2013 and only papers with the key words of interest were included: "coinitiators", "amines", "composite resins", "photopolymerization". The search used full-text papers from PubMed and Science Direct databasis. It was included only English papers, and meeting abstracts and short communications were excluded. Hand search of the references completed the review. A total of 29 articles were studied. Many coinitiators are being researched as an alternative to traditional tertiary amines, particularly in order to improve the physical and mechanical properties of the final polymer and its biocompatibility with oral tissues. Polymerizable amines, natural compounds, and coinitiators with low toxicity and antiseptic properties were studied, and the results found they would be promising substitutes. These materials must present appropriate concentration and reactivity to obtain adequate physical and mechanical properties and high biocompatibility. However, further in vivo studies are required to verify the performance of these alternative coinitiators in the composite materials, mainly when in contact with oral tissues and the stomatognathic system.

Microdureza Vickers e grau de conversão em resinas ortodônticas / Vickers microhardness and degree of conversion on orthodontic adhesives

O objetivo deste estudo foi avaliar em diferentes resinas ortodônticas a microdureza Vickers e o grau de conversão. Quatro resinas foram utilizadas: Orthobond (OB), Ortholite (OL), Concise (CO) e Transbond XT (TB). Para cada resina, cinco amostras foram obtidas, nas quais foram realizadas trinta endentações em cada superfície no microdurômetro Shimadzu (carga de 300 gramas/15 segundos). Para a avaliação do grau de conversão, duas amostras de cada monômero e polímero foram obtidas e submetidas ao ensaio de FTIR pelo método de transmissão, com resolução 2 cm-1 e 40 varreduras. Os resultados de microdureza Vickers (µHV) e grau de conversão (%) foram, respectivamente, para OB: 46 ± 17.52 (70% ±1.41), OL: 71 ±28.15 (61% ±3.53), CO: 76 ±32.70 (70% ±0.35) e TB: 73±28.40 (60% ±9.89). Os dados da µHV foram submetidos ao Teste de ANOVA e pós teste de Tukey, não apresentando diferenças estatísticas significantes entre as resinas. O conhecimento das propriedades físicas entre as resinas pode facilitar a escolha do material utilizado nos procedimentos ortodônticos.

The aim of this study was to evaluate Vickers microhardness and the degree of conversion of different orthodontic resins. Four resins were used: Orthobond (OB), Ortholite (OL), Concise (CO), and Transbond XT (TB). For each resin five samples were obtained, in which thirty indentations were made on each surface in Shimadzu microhardness (300 grams/15 seconds). To assess the degree of conversion, two samples of each monomer and polymer materials were obtained and submitted to the test of FTIR Spectrophotometry by method of transmission, toned down with resolution 2 cm-1 and 40 scans. The results of Vickers microhardness (µ HV) and degree of conversion (%) were, respectively OB: 46 ± 17.52 (70% ± 1.41); OL: 71 ± 28.15 (61% ± 3.53); CO: 76 ± 32.70 (70% ± 0.35); TB: 73 ± 28.40 (60% ± 9.89). The data were submitted to ANOVA test and Tukey post-test, and no significant statistical differences were observed between the resins. The knowledge of the physical properties between resins can facilitate the choice of the material used in orthodontic procedures.

Shrinkage stress of resin composites: effect of material - sistematic review / Tensão de contração de resinas compostas: efeito da composição do material - revisão sistemática

The longevity of resin depends on its binding between the margin of restorations and the polymer, and one factor that influences this aspect is the shrinkage stress. Thus, the working group presents the following systematic review thatverifies the influence of composite resin composition on shrinkage stress. The following electronic databases were searched: MEDLINE (via Ovid and PubMed - 2004 to January 2014), with the keywords: shrinkage stress, degree of conversion, resin composite. For shrinkage stress,, the best results were found when the BISGMA monomer was used and for the inorganic composition, an inverse relationship was observed: the increased inorganic filler content decreases shrinkage stress.

A longevidade de resina depende da sua ligação entre a margem de restaurações e o polímero, e um fator que influencia a este aspecto, é a tensão de contração. Assim, o grupo de trabalho faz a seguinte análise sistemática para verificar a influência da composição das resinas composta na tensão de contração. As seguintes bases de dados eletrônicas foram pesquisadas: MEDLINE (via PubMed e Ovídio - de 2004 a janeiro de 2014), com as palavras-chave: estresse de contração, grau de conversão, resina composta. Para tensão de contração, os melhores resultados foram encontrados quando o monômero BISGMA foi utilizada e para a composição inorgânica, uma relação inversa foi observada: o aumento do teor de carga inorgânica diminui estresse de contração.

Multivariate analysis of the spectroscopic profile of the sugar fraction of apple pomace

Pomace, the main by-product of apple juice processing, contains all the fruit's compounds such as minerals, sugars, fibers, enzymes and secondary metabolites after bioprocessing. Dried pomace from four apple varieties (Gala, Fuji, Catarina and Joaquina) was used to extract fructose, glucose, and sucrose, the main soluble sugars contained in apple pomace, to verify the possible use of the sugar fractions. The concentrated sugars were characterized by NMR and FTIR. The partial least squares method (PLS) applied to the NMR and FTIR spectra revealed large amounts of fructose, glucose, and sucrose, without the presence of others compounds. Principal component analysis (PCA) discriminated the studied apple varieties, with a 99% level of significance, as function of the amount of each sugar in the respective extracts.

Uso de fluorescência a laser no monitoramento de lesões de cáries incipientes: estudo in vivo / Use of laser fluorescence for monitoring incipient dental caries: an in vivo study

O objetivo deste estudo foi avaliar a performance do laser de diodo (DIAGNOdent, Kavo, Biberach, Alemanha) no monitoramento de lesões de cáries incipientes, não cavitadas, submetidas a fluorterapia. Foram selecionadas cinquenta e uma lesões de mancha branca diagnosticadas visualmente como ativas (aspecto rugoso e opaco) em superfícies lisas de dentes permanentes. Pacientes na faixa etária de 9 a 14 anos (n=19) foram submetidos a um programa de orientação de higiene bucal e bochechos de flúor diário (0,05 por cento) durante oito semanas. Neste intervalo, as lesões de mancha branca receberam cinco aplicações semanais de verniz fluoretado (Duraphat, Colgate). As leituras foram sempre realizadas após profilaxia e secagem na primeira (L1), quinta (L2) e nona (L3) semana do estudo a após 20 meses (L4) da leitura inicial. Os escores médios (DP) obtidos para L1, L2, L3 e L4 foram: 22,5 (15,5); 17,2 (13,9); 15,0 (13,7); 11,7 (10,8), respectivamente. O decréscimo nos escores foi significativo (p<0,05, teste t de Student pareado) para todos pares de semanas calculados exceto entre L2-L4 e L3-L4. Os dados sugerem que o DIAGNOdent pode ser útil para o monitoramento de lesões de cárie incipientes em superfícies lisas de dentes permanentes.