White mineral trioxide aggregate mixed with calcium chloride dihydrate: chemical analysis and biological properties

OBJECTIVES: This study aimed to evaluate the chemical and biological properties of fast-set white mineral trioxide aggregate (FS WMTA), which was WMTA combined with calcium chloride dihydrate (CaCl₂·2H₂O), compared to that of WMTA. MATERIALS AND METHODS: Surface morphology, elemental, and phase analysis were examined using scanning electron microscope (SEM), energy dispersive X-ray microanalysis (EDX), and X-ray diffraction (XRD), respectively. The cytotoxicity and cell attachment properties were evaluated on human periodontal ligament fibroblasts (HPLFs) using methyl-thiazol-diphenyltetrazolium (MTT) assay and under SEM after 24 and 72 hours, respectively. RESULTS: Results showed that the addition of CaCl₂·2H₂O to WMTA affected the surface morphology and chemical composition. Although FS WMTA exhibited a non-cytotoxic profile, the cell viability values of this combination were lesser than WMTA, and the difference was significant in 7 out of 10 concentrations at the 2 time intervals (p < 0.05). HPLFs adhered over the surface of WMTA and at the interface, after 24 hours of incubation. After 72 hours, there were increased numbers of HPLFs with prominent cytoplasmic processes. Similar findings were observed with FS WMTA, but the cells were not as confluent as with WMTA. CONCLUSIONS: The addition of CaCl₂·2H₂O to WMTA affected its chemical properties. The favorable biological profile of FS WMTA towards HPLFs may have a potential impact on its clinical application for repair of perforation defects.

Elemental analysis of caries-affected root dentin and artificially demineralized dentin

OBJECTIVES: This study aimed to analyze the mineral composition of naturally- and artificially-produced caries-affected root dentin and to determine the elemental incorporation of resin-modified glass ionomer (RMGI) into the demineralized dentin. MATERIALS AND METHODS: Box-formed cavities were prepared on buccal and lingual root surfaces of sound human premolars (n = 15). One cavity was exposed to a microbial caries model using a strain of Streptococcus mutans. The other cavity was subjected to a chemical model under pH cycling. Premolars and molars with root surface caries were used as a natural caries model (n = 15). Outer caries lesion was removed using a carbide bur and a hand excavator under a dyeing technique and restored with RMGI (FujiII LC, GC Corp.). The weight percentages of calcium (Ca), phosphate (P), and strontium (Sr) and the widths of demineralized dentin were determined by electron probe microanalysis and compared among the groups using ANOVA and Tukey test (p < 0.05). RESULTS: There was a pattern of demineralization in all models, as visualized with scanning electron microscopy. Artificial models induced greater losses of Ca and P and larger widths of demineralized dentin than did a natural caries model (p < 0.05). Sr was diffused into the demineralized dentin layer from RMGI. CONCLUSIONS: Both microbial and chemical caries models produced similar patterns of mineral composition on the caries-affected dentin. However, the artificial lesions had a relatively larger extent of demineralization than did the natural lesions. RMGI was incorporated into the superficial layer of the caries-affected dentin.

The effect of different fluoride application methods on the remineralization of initial carious lesions

OBJECTIVES: The purpose of this study was to assess the effect of single and combined applications of fluoride on the amount of fluoride release, and the remineralization and physical properties of enamel. MATERIALS AND METHODS: Each of four fluoride varnish and gel products (Fluor Protector, FP, Ivoclar Vivadent; Tooth Mousse Plus, TM, GC; 60 Second Gel, A, Germiphene; CavityShield, CS, 3M ESPE) and two fluoride solutions (2% sodium fluoride, N; 8% tin(ii) fluoride, S) were applied on bovine teeth using single and combined methods (10 per group), and then the amount of fluoride release was measured for 4 wk. The electron probe microanalysis and the Vickers microhardness measurements were conducted to assess the effect of fluoride application on the surface properties of bovine teeth. RESULTS: The amount of fluoride release was higher in combined applications than in single application (p < 0.05). Microhardness values were higher after combined applications of N with FP, TM, and CS than single application of them, and these values were also higher after combined applications of S than single application of A (p < 0.05). Ca and P values were higher in combined applications of N with TM and CS than single application of them (p < 0.05). They were also increased after combined applications of the S with A than after single application (p < 0.05). CONCLUSIONS: Combined applications of fluoride could be used as a basis to design more effective methods of fluoride application to provide enhanced remineralization.

Shear bond resistance and enamel surface comparison after the bonding and debonding of ceramic and metallic brackets

OBJECTIVE: To evaluate, in vitro, the shear bond strength presented by three brands of polycrystalline ceramic brackets and one brand of metallic bracket; verify the adhesive remnant index (ARI) after the tests, and analyze, through scanning electron microscopy (SEM) the enamel surface topography after debonding, detecting the release of mineral particles. METHODS: Sixty bovine lower incisors were used. Three ceramic brackets (Allure(r), InVu(r), and Clarity(r)) and one metallic bracket (Geneus(r)) were bonded with Transbond XT(r). Kruskal-Wallis's test (significance level set at 5%) was applied to the results of share bond and ARI. Mann Whitney's test was performed to compare the pairs of brackets in relation to their ARI. Brown-Forsythe's test (significance level set at 5%) was applied to the results of enamel chemical composition. Comparisons between groups were made with Games-Howell's and the Post-hoc tests. RESULTS: No statistically significant difference was observed in relation to the shear bond strength loads. Clarity(r) brackets were the most affected in relation to the surface topography and to the release of mineral particles of enamel (calcium ions). CONCLUSION: With regard to the ARI, there was a prevalence of score 4 (40.4%). As for enamel surface topography, the Geneus(r) bracket was the only one which did not show superficial tissue loss. The InVu(r) and Clarity(r) ones showed cohesive fractures in 33.3% and the Allure(r) in 50%, the latter being the one that presented most fractures during removal. .

OBJETIVO: avaliar, in vitro, a resistência ao cisalhamento apresentada por três marcas de braquetes ortodônticos cerâmicos policristalinos e uma marca de braquete metálico, verificando os índices de resina remanescentes (IRA) após os ensaios, e analisar, por meio de microscopia eletrônica de varredura, as topografias superficiais do esmalte após a descolagem, detectando o desprendimento de partículas minerais desse. MÉTODOS: foram utilizados 60 incisivos inferiores bovinos. Os braquetes cerâmicos (Allure, InVu e Clarity) e metálico (Geneus) foram colados utilizando-se o adesivo Transbond XT. Para os resultados referentes ao cisalhamento e ao IRA, foi utilizado o teste de Kruskal-Wallis, com nível de significância de 5%. A prova de Mann-Whtiney foi utilizada para comparar os diferentes tipos de braquetes aos pares, quanto ao IRA. Para a análise dos resultados referentes às composições químicas do esmalte, aplicou-se o teste de Brown-Forsythe, com significância de 5%. As comparações entre os grupos foram realizadas utilizando os testes Post Hoc e de Games-Hoewell. RESULTADOS: não foram observadas diferenças significativas quanto às cargas de cisalhamento. O Clarity foi o mais afetado em relação à topografia e ao desprendimento de partículas minerais do esmalte (íons Ca). CONCLUSÃO: em relação ao IRA, foi confirmada a prevalência do escore 4, com um percentual de 40,4%. Em relação à topografia superficial do esmalte, o Geneus foi o único que não apresentou perda de tecido . O InVu e o Clarity apresentaram fraturas coesivas de 33,3% de suas amostras, e o Allure de 50%, sendo o que mais fraturou durante a remoção. .

Mechanical properties of NiTi and CuNiTi wires used in orthodontic treatment. Part 2: Microscopic surface appraisal and metallurgical characteristics

OBJECTIVE: This research aimed at comparing the qualitative chemical compositions and the surface morphology of fracture regions of eight types of Nickel (Ni) Titanium (Ti) conventional wires, superelastic and heat-activated (GAC, TP, Ormco, Masel, Morelli and Unitek), to the wires with addition of copper (CuNiTi 27oC and 35oC, Ormco) after traction test. METHODS: The analyses were performed in a scanning electronic microscope (JEOL, model JSM-5800 LV) with EDS system of microanalysis (energy dispersive spectroscopy). RESULTS : The results showed that NiTi wires presented Ni and Ti as the main elements of the alloy with minimum differences in their composition. The CuNiTi wires, however, presented Ni and Ti with a significant percentage of copper (Cu). As for surface morphology, the wires that presented the lowest wire-surface roughness were the superelastic ones by Masel and Morelli, while those that presented the greatest wire-surface roughness were the CuNiTi 27oC and 35oC ones by Ormco, due to presence of microcavity formed as a result of pulling out some particles, possibly of NiTi. 4 The fracture surfaces presented characteristics of ductile fracture, with presence of microcavities. The superelastic wires by GAC and the CuNiTi 27oC and the heat-activated ones by Unitek presented the smallest microcavities and the lowest wire-surface roughness with regard to fracture, while the CuNiTi 35oC wires presented inadequate wire-surface roughness in the fracture region. CONCLUSION: CuNiTi 35oC wires did not present better morphologic characteristics in comparison to the other wires with regard to surfaces and fracture region. .

OBJETIVO: objetivou-se nessa pesquisa comparar as composições químicas qualitativas e as morfologias das superfícies e das regiões de fratura, após ensaios de tração, de oito tipos de fios de NiTi superelásticos e termoativados convencionais (GAC, TP, Ormco, Masel, Morelli e Unitek) aos fios com adição de cobre (CuNiTi 27°C e 35°C, da Ormco). MÉTODOS: as análises foram realizadas em microscópio eletrônico de varredura (JEOL, modelo JSM-5800 LV) com sistema de microanálise EDS (energy dispersive spectroscopy). RESULTADOS: os resultados mostraram que os fios de NiTi ensaiados apresentaram Ni e Ti como os principais elementos da liga, com diferenças mínimas em suas composições. Os fios de CuNiTi, por sua vez, apresentaram Ni e Ti, com percentual significativo de cobre (Cu). Em relação às morfologias das superfícies, os fios que apresentaram os melhores acabamentos foram os superelásticos da Masel e Morelli, e os que apresentaram os piores acabamentos foram os de CuNiTi 27°C e 35°C, da Ormco, graças à presença de microcavidades formadas devido ao arrancamento de partículas, possivelmente de NiTi 4 . As superfícies de fratura apresentaram características de fratura dúctil, com a presença de microcavidades. Os fios superelásticos da GAC e de CuNiTi 27°C, bem como os termoativados da Unitek, apresentaram as menores microcavidades e os melhores acabamentos à fratura, enquanto os fios de CuNiTi 35° apresentaram acabamentos inadequados das regiões de fratura. CONCLUSÃO: os fios de CuNiTi 35°C não apresentaram características morfológicas mais adequadas das superfícies e das regiões de fratura em relação aos demais fios. .

Annealing of Co-Cr dental alloy: effects on nanostructure and Rockwell hardness

PURPOSE: The aim of the study was to evaluate the effect of annealing on the nanostructure and hardness of Co-Cr metal ceramic samples that were fabricated with a direct metal laser sintering (DMLS) technique. MATERIALS AND METHODS: Five groups of Co-Cr dental alloy samples were manufactured in a rectangular form measuring 4 x 2 x 2 mm. Samples fabricated by a conventional casting technique (Group I) and prefabricated milling blanks (Group II) were examined as conventional technique groups. The DMLS samples were randomly divided into three groups as not annealed (Group III), annealed in argon atmosphere (Group IV), or annealed in oxygen atmosphere (Group V). The nanostructure was examined with the small-angle X-ray scattering method. The Rockwell hardness test was used to measure the hardness changes in each group, and the means and standard deviations were statistically analyzed by one-way ANOVA for comparison of continuous variables and Tukey's HSD test was used for post hoc analysis. P values of <.05 were accepted as statistically significant. RESULTS: The general nanostructures of the samples were composed of small spherical entities stacked atop one another in dendritic form. All groups also displayed different hardness values depending on the manufacturing technique. The annealing procedure and environment directly affected both the nanostructure and hardness of the Co-Cr alloy. Group III exhibited a non-homogeneous structure and increased hardness (48.16 +/- 3.02 HRC) because the annealing process was incomplete and the inner stress was not relieved. Annealing in argon atmosphere of Group IV not only relieved the inner stresses but also decreased the hardness (27.40 +/- 3.98 HRC). The results of fitting function presented that Group IV was the most homogeneous product as the minimum bilayer thickness was measured (7.11 A). CONCLUSION: After the manufacturing with DMLS technique, annealing in argon atmosphere is an essential process for Co-Cr metal ceramic substructures. The dentists should be familiar with the materials that are used in clinic for prosthodontics treatments.

Effects of 45S5 bioglass on surface properties of dental enamel subjected to 35% hydrogen peroxide / 国际口腔科学杂志·英文版

Tooth bleaching agents may weaken the tooth structure. Therefore, it is important to minimize any risks of tooth hard tissue damage caused by bleaching agents. The aim of this study was to evaluate the effects of applying 45S5 bioglass (BG) before, after, and during 35% hydrogen peroxide (HP) bleaching on whitening efficacy, physicochemical properties and microstructures of bovine enamel. Seventy-two bovine enamel blocks were prepared and randomly divided into six groups: distilled deionized water (DDW), BG, HP, BG before HP, BG after HP and BG during HP. Colorimetric and microhardness tests were performed before and after the treatment procedure. Representative specimens from each group were selected for morphology investigation after the final tests. A significant color change was observed in group HP, BG before HP, BG after HP and BG during HP. The microhardness loss was in the following order: group HP>BG before HP, BG after HP>BG during HP>DDW, BG. The most obvious morphological alteration of was observed on enamel surfaces in group HP, and a slight morphological alteration was also detected in group BG before HP and BG after HP. Our findings suggest that the combination use of BG and HP could not impede the tooth whitening efficacy. Using BG during HP brought better protective effect than pre/post-bleaching use of BG, as it could more effectively reduce the mineral loss as well as retain the surface integrity of enamel. BG may serve as a promising biomimetic adjunct for bleaching therapy to prevent/restore the enamel damage induced by bleaching agents.

Characterization of calcium oxide in root perforation sealer materials

Root perforation represents an undesirable complication that may lead to an unfavorable prognosis. The aims of this study were to characterize and to compare the presence of calcium oxide (CaO) on the chemical composition of materials used for root perforation therapy: gray and white mineral trioxide aggregate (MTA) and Portland cement (PC), gray MTA+5%CaO and gray MTA+10%CaO. The last two materials were analyzed to evaluate the increase of CaO in the final sample. CaO alone was used as a standard. Eighteen polyethylene tubes with an internal diameter of 3 mm and 3 mm in length were prepared, filled and then transferred to a chamber with 95% relative humidity and a temperature of 37ºC. The chemical compounds (particularly CaO) and the main components were analyzed by energy-dispersive X-ray microanalysis (EDX). EDX revealed the following concentrations of CaO: gray MTA: 59.28%, white MTA: 63.09%; PC: 72.51%; gray MTA+5%CaO: 63.48% and gray MTA+10%CaO: 67.55%. The tested materials presented different concentrations of CaO. Even with an increase of 5 and 10% CaO in gray MTA, the CaO levels found in the MTA samples were lower than those found in PC.

A perfuração do canal radicular representa uma complicação indesejável que sugere um prognóstico desfavorável. Os objetivos deste estudo foram caracterizar e comparar a presença de óxido de cálcio (CaO) na composição química de vários materiais utilizados no tratamento de perfurações radiculares. Foram analisados os materiais MTA cinza e branco, cimento Portland e na tentativa de se observar o aumento nos valores de CaO foram testados MTA cinza+5% de óxido de cálcio, MTA cinza+10% de óxido de cálcio e o CaO (padrão). Foram preparados 18 tubos de polietileno com diâmetro interno e comprimento de 3 mm. Estes foram preenchidos e depois transferidos para uma estufa com umidade relativa de 95% e temperatura de 37°C. Os compostos químicos (principalmente o óxido de cálcio) e os principais componentes foram avaliados por espectrometria de dispersão de raios-X (EDX). A análise por EDX revelou as seguintes concentrações de CaO: 59,28% no MTA cinza; 63,09% no MTA branco; 72,51% no cimento Portland; 63,48% no MTA cinza+5% de CaO; 67,55% no MTA cinza+10% de CaO. Os materiais testados apresentaram diferentes concentrações de CaO. Mesmo com o acréscimo de CaO nas concentrações de 5 e 10% ao MTA cinza, os valores de CaO foram inferiores aos observados no cimento Portland.

Retrieval analysis of different orthodontic brackets: the applicability of electron microprobe techniques for determining material heterogeneities and corrosive potential

OBJECTIVE: The objective of this study was to investigate the applicability of micro-analytical methods with high spatial resolution to the characterization of the composition and corrosion behavior of two bracket systems. MATERIAL AND METHODS: The surfaces of six nickel-free brackets and six nickel-containing brackets were examined for signs of corrosion and qualitative surface analysis using an electron probe microanalyzer (EPMA), prior to bonding to patient's tooth surfaces and four months after clinical use. The surfaces were characterized qualitatively by secondary electron (SE) images and back scattered electron (BSE) images in both compositional and topographical mode. Qualitative and quantitative wavelength-dispersive analyses were performed for different elements, and by utilizing qualitative analysis the relative concentration of selected elements was mapped two-dimensionally. The absolute concentration of the elements was determined in specially prepared brackets by quantitative analysis using pure element standards for calibration and calculating correction-factors (ZAF). RESULTS: Clear differences were observed between the different bracket types. The nickel-containing stainless steel brackets consist of two separate pieces joined by a brazing alloy. Compositional analysis revealed two different alloy compositions, and reaction zones on both sides of the brazing alloy. The nickel-free bracket was a single piece with only slight variation in element concentration, but had a significantly rougher surface. After clinical use, no corrosive phenomena were detectable with the methods applied. Traces of intraoral wear at the contact areas between the bracket slot and the arch wire were verified. CONCLUSION: Electron probe microanalysis is a valuable tool for the characterization of element distribution and quantitative analysis for corrosion studies.

Efeito do silício na intensidade da cercosporiose e na nutrição mineral de mudas de cafeeiro / Effect of silicon on the intensity of brown eye spot and on the mineral nutrition of coffee seedlings

O presente trabalho objetivou estudar o efeito do silício na intensidade da cercosporiose e na nutrição mineral de mudas de cafeeiro. No experimento 1, testou-se seis doses de ácido silícico (0, 0,5; 1; 2; 4 e 6 g kg­1 de solo) em mudas da cultivar Catuaí Vermelho IAC 99 inoculadas com o fungo Cercospora coffeicola. No experimento 2, foram realizadas microanálises de raios-X para a avaliação de nutrientes presentes nas folhas das mudas de cafeeiro das cultivares Topázio MG1190 e Icatu Precoce IAC 3282, inoculadas e não inoculadas com C. coffeicola, com e sem silicato de cálcio (1 g kg-1 de solo). Com o aumento das doses de ácido silícico observou-se redução na área abaixo da curva de progresso do número de lesões por folha (AACPNLF), redução linear nos teores foliares de magnésio e fósforo e aumento nos teores de enxofre e cobre. Os teores foliares de boro apresentaram comportamento quadrático, diminuindo com o aumento das doses de ácido silícico e aumentando a partir da dose de 4 g kg-1 de solo. Em microanálise de raio X, mudas de cafeeiro com cercosporiose apresentam menores picos de potássio e cálcio, independente da cultivar utilizada.

Our objective was to verify the effect of silicon on the intensity of brown eye spot and on the mineral nutrition of coffee seedlings. In the first experiment, 6 doses of silicic acid (0, 0.5, 1, 2, 4 and 6 g kg-1 soil) were tested using a complete randomized block design with 4 replicates with 6 coffee seedlings cultivar Catuaí Vermelho IAC 99 inoculated with the fungus Cercospora coffeicola. In the second experiment, X-ray microanalysis in a scanning electron microscope was performed on 2 coffee cultivars (Topazio MG1190 and Icatu Precoce IAC 3282), inoculated and non-inoculated with C. coffeicola, treated and untreated with calcium silicate (1 g kg-1 of soil). With the increase of the silicic acid doses, there was observed a reduction in the area under the disease progress curve of the number of lesions per leaf (AUPCNLL), coupled with a linear reduction in the foliar contents of magnesium and phosphorus as well as an increase in the contents of sulfur and copper. The foliar contents of boron presented a quadratic behavior, decreasing with the increase of silicic acid and increasing with the dose of 4 g kg-1 of soil. In X-ray microanalysis, coffee seedlings with brown eye spot presented lower peaks of potassium and calcium, regardless of the cultivar used.

Study on electrical current mark with environmental scanning electron microscopy and energy dispersive X-ray microanalyser / 法医学杂志

OBJECTIVE@#To provide objective proof on diagnosis of electrical current mark in electrocution, the environmental scanning electron microscopy and energy dispersive X-ray microanalyser (ESEM-EDX) were adopted to study the microscopic morphological characteristics and elemental composition of electrical current mark.@*METHODS@#Morphological characteristics of electrical current marks, the elemental composition and morphology of metal particles were studied with ESEM-EDX.@*RESULTS@#The electroporation and metal melted beads could be found in the electrical current marks and skin around them. The metal melted beads mainly composed of common metal such as iron, copper, aluminum and some uncommon metal including gold, titanium and barium.@*CONCLUSION@#ESEM-EDX can be applied in forensic diagnosis of electrocution.

Advances in rapid prenatal detection of fetal chromosome abnormalities / 中华男科学杂志

Rapid prenatal detection methods, including molecular cytogenetic analysis and ultrasonographic markers, are very important for prenatal diagnosis. The use of molecular cytogenetic techniques has significantly improved the rapid detection of aneuploidy and identification of small structural abnormalities of fetal chromosomes. At present, commonly used molecular cytogenetic techniques include fluorescence in situ hybridization (FISH), quantitative fluorescence PCR (QF-PCR), multiplex ligation-dependent probe amplification (MLPA) and microarray-based comparative genomic hybridization (array CGH). There is extensive evidence that major chromosomal abnormalities can be effectively detected by ultrasonography in the first and second trimesters of pregnancy. So we can combine molecular cytogenetic techniques with ultrasonographic markers to improve the identification of aneuploidies for chromosomes and the accuracy of prenatal diagnosis, and to reduce birth defects in newborns.

Spectroscopic techniques in the development of glass ionomer cements

Glass ionomer cement [GIC] is a relatively recent development in the field of restorative materials in dental treatment. The setting of GIC is a complex process based on acid-base reaction and may vary with the composition of the ionomer. Various spectroscopic techniques have been applied to understand the nature and duration of the [BC setting process. The techniques include ultraviolet [UV] and visible spectroscopy, infrared [IR] spectroscopy, Fourier-transform infrared [FT-IR] spectroscopy. nuclear magnetic resonance [NMR] spectroscopy, Fluorescence Spectroscopy, kaman spectroscopy, mass spectroscopy. atomic absorption spectroscopy as well as electron probe microanalysis [FYMA] and have been presented in this article

Optical density and chemical composition of microfilled and microhybrid composite resins

This study evaluated the optical density of two microfilled and two microhybrid resins, as well as the composition of these materials with regard to their optical density. Cavities prepared in 12 2-mm- or 4-mm-thick acrylic plastic plates were filled with Z250 (3M-ESPE), A110 (3M-ESPE), Charisma (Heraeus-Kulzer) and DurafillVS (Heraeus-Kulzer). The resin increments (2-mm-thick) were light-cured for 40 s. Three 0.12-s radiographic exposures were made of each #2 acrylic plastic plate. DenOptix system optical plates were used to obtain the digital images. Three readings of the composite resin surface were made in each radiograph, totalizing 216 readings. The mean of highest and lowest grey-scale values was obtained. Two specimens of each composite resin were prepared for SEM analysis of the chemical elements related to optical density, using energy dispersive x-ray analysis (EDX). The results were subjected to Shapiro-Wilk's test, ANOVA, Tukey's test at 1 percent level of significance and Pearson's correlation. The mean grey-scale values at 2 mm and 4 mm were: Z250 = 154.27a and 185.33w; A110 = 46.77b and 63.05y; Charisma = 163.40c and 200.46z; DurafillVS = 43.92b and 58.99x, respectively. Pearson's test did not show any positive correlation between optical density and percentage weight of optical density chemical elements. It was concluded that the microhybrid resins had higher optical density means than the microfilled resins; among the evaluated resins, Charisma had the highest optical density means.

Bone response to a Ca- and P-enriched titanium surface obtained by anodization

This study evaluated bone response to a Ca- and P- enriched titanium (Ti) surface treated by a multiphase anodic spark deposition coating (BSP-AK). Two mongrel dogs received bilateral implantation of 3 Ti cylinders (4.1 x 12 mm) in the humerus, being either BSP-AK treated or untreated (machined - control). At 8 weeks postimplantation, bone fragments containing the implants were harvested and processed for histologic and histomorphometric analyses. Bone formation was observed in cortical area and towards the medullary canal associated to approximately 1/3 of implant extension. In most cases, in the medullary area, collagen fiber bundles were detected adjacent and oriented parallel to Ti surfaces. Such connective tissue formation exhibited focal areas of mineralized matrix lined by active osteoblasts. The mean percentages of bone-to-implant contact were 2.3 (0.0-7.2 range) for BSP-AK and 0.4 (0.0-1.3 range) for control. Although the Mann-Whitney test did not detect statistically significant differences between groups, these results indicate a trend of BSP-AK treated surfaces to support contact osteogenesis in an experimental model that produces low bone-to-implant contact values.

O objetivo desse estudo foi avaliar a resposta do tecido ósseo à superfície de titânio (Ti) enriquecida com Ca e P obtida por anodização (BSP-AK). Três cilindros de Ti (4,1 x 12 mm) BSP-AK ou usinado (controle) foram implantados bilateralmente nos úmeros de dois cães de raça indefinida. Oito semanas após a implantação, os fragmentos ósseos contendo os implantes foram removidos e processados para análises histológica e histomorfométrica. A formação óssea foi observada na região cortical e no canal medular até aproximadamente um terço da extensão do implante. Na maioria dos casos, feixes de fibras colágenas dispostos paralelamente à superfície do implante foram observados na região medular. Nessa região observaram-se também áreas focais de formação de matriz mineralizada e osteoblastos ativos. Os implantes do grupo BSP-AK apresentaram média de contato osso-implante 2,3 por cento, com medidas variando de 0,0 a 7,2 por cento e os do grupo controle tiveram média 0,4 por cento, com medidas variando de 0,0 a 1,3 por cento. Apesar do teste de Mann-Whitney não mostrar diferença estatisticamente significante entre os grupos, nossos resultados indicaram uma tendência para a ocorrência de osteogênese de contato na superfície BSP-AK em um modelo experimental que resulta em baixos valores de contato osso-implante.

Comparative analysis of various corrosive environmental conditions for NiTi rotary files / 대한치과보존학회지

The aim of the present study is to compare the corrosion tendency using two kinds of NiTi files in the various environmental conditions through the visual examination and electrochemical analysis. ProTaper Universal S2, 21 mm (Dentsply Maillefer, Ballaigues, Switzerland) and Hero 642, 0.06 tapers, size 25, 21 mm (Micromega, Besancon, France) rotary instruments were tested. The instruments were randomly divided into eighteen groups (n = 5) by the immersion temperature, the type of solution, the brand of NiTi rotary instrument and the presence of mechanical loading. Each file was examined at various magnifications using Scanning Electron Microscope (JEOL, Akishima, Tokyo, Japan) equipped with energy dispersive X-ray microanalysis (EDX). EDX was used to determine the components of the endodontic file alloy in corroded and noncorroded areas. The corrosion resistance of unused and used NiTi files after repeated uses in the human teeth was evaluated electrochemically by potentiodynamic polarization test using a potentiostat (Applied Corrosion Monitoring, Cark-in-Cartmel, UK). Solution temperature and chloride ion concentration may affect on passivity of NiTi files. Under the conditions of this in vitro study, the corrosion resistance is slightly increased after clinical use.

Morphological and chemical analysis of bone substitutes by scanning electron microscopy and microanalysis by spectroscopy of dispersion energy

This study evaluated the morphological and chemical composition of the following bone substitutes: cancellous and cortical organic bovine bone with macro and microparticle size ranging from 1.0 to 2.0 mm and 0.25 to 1.0 mm, respectively; inorganic bovine bone with particle size ranging from 0.25 to 1.0 mm; hydroxyapatite with particle size ranging from 0.75 to 1.0 mm; and demineralized freeze-dried bone allograft with particle size ranging from 0.25 to 0.5 mm. The samples were sputter-coated with gold in an ion coater, the morphology was observed and particle size was measured under vacuum by scanning electron microscopy (SEM). The chemical composition was evaluated by spectroscopy of dispersion energy (EDS) microanalysis using samples without coating. SEM analysis provided visual evidence that all examined materials have irregular shape and particle sizes larger than those informed by the manufacturer. EDS microanalysis detected the presence of sodium, calcium and phosphorus that are usual elements of the bone tissue. However, mineral elements were detected in all analyzed particles of organic bovine bone except for macro cancellous organic bovine bone. These results suggest that the examined organic bovine bone cannot be considered as a pure organic material.

Neste estudo foram avaliados a morfologia, o tamanho e a composição química dos seguintes substitutos ósseos: osso bovino orgânico cortical e esponjoso com micropartículas medindo entre 0,25 e 1,0 mm e macropartículas medindo entre 1,0 e 2,0 mm; osso bovino cortical inorgânico com partículas medindo entre 0,25 e 1,0 mm; hidroxiapatita com partículas medindo entre 0,75 e 1,0 mm; e osso humano descalcificado, congelado e seco medindo entre 0,25 a 0,5 mm. Para a analise da morfologia e tamanho das partículas, as amostras foram preparadas em porta-espécime, metalizadas em ouro e analisadas a vácuo em microscopia eletrônico de varredura (MEV). Para a análise da composição química, as partículas não foram metalizadas e foram analisadas por microanálise por espectroscopia por dispersão de energia (EDS). A análise em MEV, demonstrou que as partículas substitutos ossos apresentaram formato irregular e tamanho variável, maior do que o mencionado pelo fabricante. A microanálise por EDS detectou a presença de elementos como sódio, cálcio e fósforo, que são comuns à composição do tecido ósseo, porém revelaram a presença de elementos químicos nas partículas de osso bovino orgânico, exceto para a macropartícula de osso bovino orgânico esponjoso. Esses resultados sugerem que o osso bovino orgânico não pode ser considerado um material orgânico puro.

Isolation and characterization of calcium phosphate crystals in the human articular knee cartilages and intervertebral discs: an electron microscopic study

The multiple complains of pain resulting from intervertebral disc prolapse or osteoarthritic knee joint is one of the most significant neurosurgical and orthopaedic disorders in industrialized society. The exact relationship between calcium phosphate crystal deposition and these diseases remains obscure, although there is evidence supporting a rapid degenerative arthropathy within a specific set of patients. Several basic calcium phosphate crystals have been reported to be associated with osteoarthritis joint diseases as well as in lumbar disc prolapse patients. To compare the presence and characters of calcium phosphate crystals in normal and osteoarthritic human articular knee cartilages as well as in degenerated disc patients. Five normal articular knee cartilages and intervertebral discs were taken from human cadavers at the dissection room, Faculty of Medicine, Taibah University. Osteoarthritic articular cartilage, and disc prolapse, fifteen specimens each, were obtained from Saudi German, Madinah National Hospitals; and Alexandria University Hospital respectively. Specimens were examined by light and electron microscopy, and electron probe x-ray microanalysis. No crystals could be detected at the light microscopic level. By electron microscopy, crystals were detected in cartilages from all pathological sites sampled. Few or no crystals were observed in normal articular knee cartilages and intervertebral discs. Coexistence of calcium pyrophosphate dihydrate and cuboid calcium phosphate crystals was seen in all cases. Identification was based on the distinctive morphology, size range and XRMA spectrum. The results of this research confirmed the density of calcium phosphate and pyrophosphate dehydrate crystals in osteoarthritic cartilage, and degenerated disc that may provide a useful diagnostic and therapeutic approach to osteoarthritis and disc prolapse patients

Morphology of the lateral pterygoid muscle associated to the mandibular condyle in the human prenatal stage

El músculo pterigoideo lateral (MPL) establece una relación directa con el cóndilo y el disco articular, desempeñando un rol importante en el movimiento mandibular a través del complejo articular temporomandibular (CATM). El objetivo de este trabajo fue determinar la correspondencia entre las características morfológicas de los haces musculares del MPL y el grado de mineralización del cóndilo mandibular en la etapa prenatal, mediante un análsisi estructgural, ultraestructural y microanalítico. Se utilizaron 16 fetos humanos de 11 a 37 semanas de gestación, procedentes de abortos espontáneos y sin patologías aparentes. Se obtuvieron muestras del músculo pterigoideo lateral y cóndilo mandibular, para ser examinadas meidante microscopía ñoptica, electrónica y técnicas de microanálisis. Muestras incluidas en parafina se emplearon en los estudios de inmunomarcación con desmina (dilución 1:25 Dako) y alfa actina sarcómerica (dilución 1:50 Dako), visualizados con sistema avidina-biotina. El lado contralateral de cada una se utilizó para microscopía electrónica de transmisión. En 4 cóndilos de 17 y 21 semanas de desarrollo se analizó el contenido relativo de calcio y fósforo con la técnica microanalítica por difracción de rayos X. Entre las 11 y 16 semanas, el MPL estuvo contituido por miotubos secundarios asociados a céluals satélites y fascículos. La organización del músculo a las 37 semanas fue más compleja, con aspecto multipeniforme y con la edad se redujo la intensidad de la inmunomarcación con alfa actina sarcomérica. Estos resultados sugieren que entre las 16 y 22 semanas, el proceso de diferenciación y maduración de las fibras musculares precede y prevalece sobre el desarrollo y mineralización del cóndilo mandibular. La funcionalidad aún rudimentaria del MPL prenatal sería uno de los factores reguladores del proceso de osificación a nivel del cóndilo mandibular, cuyo ritmo aumentaría a partir de las 22 semanas de gestación

Identification of lipstick smear by energydispersive X-ray analysis and spectrophotometer

Lipstick smear is one of the most frequently encountered trace evidence at the crime scene. It is one of the variable samples to prove the relationship between the suspect and victim or the crime scene. So, the present study was done on 100 different types of lipstick. In this study a combination between visual comparison, energy dispersive X-ray analysis and spectrophotometer have been shown to be suitable for analysis, characterization and discrimination of small quantities of lipsticks, which may be encountered in forensic field. Visual comparison of lipstick smears in the present study classified them into six groups; light red, 22 samples; dark red, 20; pink, 18; orange, 4; light brown, 15 and dark brown, 21. By energy dispersive X-ray analysis, the present study revealed 10 elements such as Aluminum, Silicon, Sulphur, Chloride, Potassium, Calcium; Titanium, Iron, Cupper and Zinc. The level of each element differed in different types of lipstick smears. Spectrophotometeric analysis of lipsticks revealed an absorption spectrum ranging between [200-800nm], providing a fingerprint for qualitatively identifying the lipsticks. Also this method was used for quantitative analysis purposes. The amount of visible light or other radiant energy absorbed by a lipstick solution was measured; it depended on the concentration [50 ug/ml, 100 ug/ml, 150 ug/ml], which gave different absorbance levels in the same wavelength. The present study concluded that spectrophotometric method could be applied to traces from lipstick smears. Simultaneous measurement of transmittance profiles in visible and ultra violet regions enabled us not only to evaluate their colours in visible region but also to clarify the chemicals by the transmittance profiles in ultra violet region, because the latter region reflects the characteristics of dyestuffs. On the other hand, the non-destructive method [energy dispersive X-ray analysis] was more suitable for identification of trace amount of lipsticks for forensic investigation because X-rays analysis was performed directly on materials bearing the stain