RESUMO
PURPOSE: This study compared the use of anatomical glass fiber posts using bulk-fill composite resin with computer-aided design and computer-aided manufacturing (CAD/CAM) milled glass fiber post in oversized root canals, through bond strength (BS) and fracture resistance (FR) tests (fracture load). METHODS AND MATERIALS: A total of 48 mandibular premolars were selected, half of them had their crowns removed at the cemento-enamel junction (CEJ) and the other half were sectioned 2 mm above the CEJ. Subsequently, teeth were endodontically treated. After 1 week, the standard preparation of the canals was carried out, and the roots were divided into three groups (n=16), according to the use of different restorative techniques (control: prefabricated glass fiber post [PFP], direct anatomical glass fiber post [AFP], and CAD/CAM milled glass fiber post [MFP]). After luting procedures using Single Bond Universal and RelyX Ultimate (3M ESPE), for eight teeth in each group, six specimens were obtained (two slices from each root third: cervical, middle, and apical). For the remaining eight roots of each group, standardized preparations for metal-free crowns, milling of 5 mol% yttria-stabilized tetragonal zirconia polycrystalline, cementation of the crowns, and periodontal ligament simulation were performed. Then, for each group, the BS was evaluated through the push-out test, and the FR was evaluated in compression. The data obtained from BS were submitted to two-way analysis of variance (ANOVA; group vs root region) and Tukey (α=0.05) and from FR to one-way ANOVA (group) and Tukey (α=0.05). RESULTS: For the BS test, the MFP group was statistically superior to the PFP group in all root regions and was statistically superior to the AFP group only in the cervical region, being statistically similar in the middle and apical root regions. For the FR test, the MFP group was statistically superior to the PFP and AFP groups. CONCLUSION: The milled fiber post technique can be a legitimate alternative in the restoration of weakened roots with flared root canals.
Assuntos
Cavidade Pulpar , alfa-Fetoproteínas , Colo do Dente , Desenho Assistido por Computador , Análise de VariânciaRESUMO
PURPOSE: To evaluate the immediate microshear resin-enamel bond strength (µSBS) and the immediate and 6-month microtensile bond strength (µTBS) and nanoleakage (NL) of the adhesive interface performed by different pHs of 40% meta-phosphoric acid (MPA) were compared with conventional 37% ortho-phosphoric acid (OPA) under different application times. Additionally, the enamel etching patterns were evaluated and the chemical/morphological changes induced by these differents groups were evaluated. MATERIALS AND METHODS: One hundred and ninety-eight extracted human molars were randomly assigned into experimental groups according to the combination of independent variables: Acid [37% ortho-phosphoric acid (OPA), 40% meta-phosphoric acid (MPA) at pHs of: 0.5, 1 and 2] and Application Time [7, 15 and 30s]. Enamel-bond specimens were prepared and tested under µSBS. Resin-dentin beams were tested under µTBS tested immediately or after 6-months of water storage. Nanoleakage was evaluated using bonded-beams of each tooth/time-period. Enamel etching pattern and chemical and ultra-morphology analyses were also performed. The µSBS (MPa) data were subjected to a two-way repeated measures ANOVA (Acid vs. Application time). For µTBS, Acid vs application time vs storage time data were subjected to three-way ANOVA and Tukey's test (α = 0.05). RESULTS: MPA pH 0.5 showed µTBS similar to OPA, independently of the application time on enamel (p>0.05) or dentin (p>0.05). OPA provided higher nanoleakage values than MPA (p = 0.003). Significant decreases in TBS and increases in NL were only observed for OPA after 6 months (p = 0.001). An increase in the application time resulted in a more pronounced etching pattern for MPA. Chemical analysis showed that dentin demineralized by MPA depicted peaks of brushite and octacalcium phosphate. MPA exposed less collagen than OPA. However, optimal results for MPA were dependent on pH/application time. CONCLUSION: The use of 40% meta-phosphoric acid with a pH of 0.5 is an alternative acid-etching agent for dentin and enamel bonding. Furthermore, the use of MPA preserves the resin-dentin interface over a 6-months period, due to presence of brushite and octacalcium phosphate and a reduced demineralization pattern.
Assuntos
Colagem Dentária , Esmalte Dentário/química , Esmalte Dentário/efeitos dos fármacos , Ácidos Fosfóricos/química , Ácidos Fosfóricos/farmacologia , Resinas Sintéticas/química , Humanos , Concentração de Íons de Hidrogênio , Isomerismo , Resistência à TraçãoRESUMO
Fue evaluado el efecto del grabado de la dentina radicular con EDTA en la resistencia de unión (RU) inmediata (IM) y después de termociclaje (TM) de un cemento autoadhesivo (AA) y uno auto grabador (AG) para la cementación de postes de fibra de vidrio. Fueron utilizadas 40 raíces de premolares humanos divididas en 4 grupos según tipo de cementación (n=10) G1 RelyX U100 (UC) según indicaciones del fabricante(IF); G2 grabado con EDTA 24% por 60 s antes de la aplicación del UC ; G3 Para Post Para Core Automix (PC) (IF)G4 - grabado con EDTA 24% por 60 s antes de la aplicación del (PC).Las raíces fueron cortadas en discos de 1 mm (dos discos por tercio radicular), la mitad de los discos fueron sometidos a ensayo expulsión IM (0,5mm/min) y la otra mitad después de TM (5º C e 55º C).los datos fueron analizados en test de ANOVA y Tukey (?=0,05).dando como resultado que el grabado con EDTA altero negativamente los valores de RU solo del tercio cervical en los dos cementos. Cuando fue comparado TM con IM con o sin aplicación de EDTA no se encontraron diferencias estadísticas significativas. Para todos los grupos testados.El cemento PC obtuvo mayores valores de RU (19,59 MPa) comparado con el UC (15,80 MPa).concluyéndose que el tratamiento con EDTA afecto la RU solo para el tercio cervical tanto en IM como TM en los dos cementos. El TM con o sin EDTA no afecto los valores de RU cuando comparado con IM
The effect of post-space treatment whit EDTA on the bond strength (BS) of fiber posts in different root regions was evaluated using two different type of resin cements Rely X U100 (UC) and Para Post Para Core automix (PC) . Fourty extracted premolars root canals were assigned to four groups of 10 roots each. G1 RelyX U100 (UC) according to manufacturer's instructions (MI), G2 etching whit EDTA 24% for 60 s before application of UC; G3 Para Post Para Core Automix (PC) MI; G4 Etching whit EDTA 24% for 60s before application off PC. After cementation the roots were sectioned in 6 slices 1mm each (two slides for root region) and randomly divided into two subgroups, depending on testing time immediate (IM) vs. after termocicling(TM) ), for expulsion test. Statistical analysis was performed with ANOVA and Tukey test (?=.05) No differences in BS was found among the groups whit and whit out EDTA 24 %. Etching whit EDTA adversely alter the BS values of the cervical third in the two cements. When TM was compared with IM with or without application of EDTA there was no statistically significant difference. For all groups tested, PC show higher values of BS (19.59 MPa) was compared with UC (15.80 MPa). Concluded that treatment with EDTA affected the BS only on the cervical third in both IM and TM in the two cements. The TM with or without EDTA did not affect the values of BS when compared with IM
Assuntos
Humanos , Ácido Edético , Ácido Edético/uso terapêutico , Cimentos de Resina/uso terapêutico , Dentina/patologia , Moldes Cirúrgicos , Selantes de Fossas e Fissuras/uso terapêuticoRESUMO
This study was carried out to compare the physiochemical quality of honeys from beekeepers in northern Zona da Mata, MG, and honeys from warehouses registered at the Serviço de Inspeção Federal (SIF) in the State of Minas Gerais. Physiochemical analysis involving 39 samples were done, with three samples from each of the 13 beekeepers and 18 samples from warehouses registered at SIF-MG. Differences in quality from the two origins occurred in: free acidity, ashes, hydroxymethylfurfural, apparent sucrose and insoluble solids, where honeys from warehouses were of better quality. In addition, for free acidity and insoluble solids, two samples from northern Zona da Mata showed values above the established by the Instrução Normativa n°11 relative to the year 2000, whereas the values for insoluble solids in 11 samples from northern Zona da Mata and 2 samples from warehouses were in disagreement with this legislation.(AU)
Assuntos
Animais , Mel/análise , Criação de Abelhas/métodosRESUMO
This study was carried out to compare the physiochemical quality of honeys from beekeepers in northern Zona da Mata, MG, and honeys from warehouses registered at the Serviço de Inspeção Federal (SIF) in the State of Minas Gerais. Physiochemical analysis involving 39 samples were done, with three samples from each of the 13 beekeepers and 18 samples from warehouses registered at SIF-MG. Differences in quality from the two origins occurred in: free acidity, ashes, hydroxymethylfurfural, apparent sucrose and insoluble solids, where honeys from warehouses were of better quality. In addition, for free acidity and insoluble solids, two samples from northern Zona da Mata showed values above the established by the Instrução Normativa n°11 relative to the year 2000, whereas the values for insoluble solids in 11 samples from northern Zona da Mata and 2 samples from warehouses were in disagreement with this legislation.
Assuntos
Animais , Mel/análise , Criação de Abelhas/métodosRESUMO
Histamine release induced by plant lectins was studied with emphasis on the carbohydrate specificity, external calcium requirement, metal binding sites, and mast cell heterogeneity and on the importance of antibodies bound to the mast cell membrane to the lectin effect. Peritoneal mast cells were obtained by direct lavage of the rat peritoneal cavity and guinea pig intestine and hamster cheek pouch mast cells were obtained by dispersion with collagenase type IA. Histamine release was induced with concanavalin A (Con A), lectins from Canavalia brasiliensis, mannose-specific Cymbosema roseum, Maackia amurensis, Parkia platycephala, Triticum vulgaris (WGA), and demetallized Con A and C. brasiliensis, using 1-300 microg/ml lectin concentrations applied to Wistar rat peritoneal mast cells, peaking on 26.9, 21.0, 29.1, 24.9, 17.2, 10.7, 19.9, and 41.5%, respectively. This effect was inhibited in the absence of extracellular calcium. The lectins were also active on hamster cheek pouch mast cells (except demetallized Con A) and on Rowett nude rat (animal free of immunoglobulins) peritoneal mast cells (except for mannose-specific C. roseum, P. platycephala and WGA). No effect was observed in guinea pig intestine mast cells. Glucose-saturated Con A and C. brasiliensis also released histamine from Wistar rat peritoneal mast cells. These results suggest that histamine release induced by lectins is influenced by the heterogeneity of mast cells and depends on extracellular calcium. The results also suggest that this histamine release might occur by alternative mechanisms, because the usual mechanism of lectins is related to their binding properties to metals from which depend the binding to sugars, which would be their sites to bind to immunoglobulins. In the present study, we show that the histamine release by lectins was also induced by demetallized lectins and by sugar-saturated lectins (which would avoid their binding to other sugars). Additionally, the lectins also released histamine from Rowett nude mast cells that are free of immunoglobulins.
Assuntos
Liberação de Histamina/efeitos dos fármacos , Mastócitos/efeitos dos fármacos , Lectinas de Plantas/farmacologia , Animais , Cricetinae , Feminino , Cobaias , Masculino , Mastócitos/metabolismo , Ratos , Ratos WistarRESUMO
Histamine release induced by plant lectins was studied with emphasis on the carbohydrate specificity, external calcium requirement, metal binding sites, and mast cell heterogeneity and on the importance of antibodies bound to the mast cell membrane to the lectin effect. Peritoneal mast cells were obtained by direct lavage of the rat peritoneal cavity and guinea pig intestine and hamster cheek pouch mast cells were obtained by dispersion with collagenase type IA. Histamine release was induced with concanavalin A (Con A), lectins from Canavalia brasiliensis, mannose-specific Cymbosema roseum, Maackia amurensis, Parkia platycephala, Triticum vulgaris (WGA), and demetallized Con A and C. brasiliensis, using 1-300 æg/ml lectin concentrations applied to Wistar rat peritoneal mast cells, peaking on 26.9, 21.0, 29.1, 24.9, 17.2, 10.7, 19.9, and 41.5 percent, respectively. This effect was inhibited in the absence of extracellular calcium. The lectins were also active on hamster cheek pouch mast cells (except demetallized Con A) and on Rowett nude rat (animal free of immunoglobulins) peritoneal mast cells (except for mannose-specific C. roseum, P. platycephala and WGA). No effect was observed in guinea pig intestine mast cells. Glucose-saturated Con A and C. brasiliensis also released histamine from Wistar rat peritoneal mast cells. These results suggest that histamine release induced by lectins is influenced by the heterogeneity of mast cells and depends on extracellular calcium. The results also suggest that this histamine release might occur by alternative mechanisms, because the usual mechanism of lectins is related to their binding properties to metals from which depend the binding to sugars, which would be their sites to bind to immunoglobulins. In the present study, we show that the histamine release by lectins was also induced by demetallized lectins and by sugar-saturated lectins (which would avoid their binding to other sugars). Additionally, the lectins also released histamine from Rowett nude mast cells that are free of immunoglobulins.
Assuntos
Animais , Cricetinae , Feminino , Cobaias , Masculino , Ratos , Liberação de Histamina/efeitos dos fármacos , Mastócitos/efeitos dos fármacos , Lectinas de Plantas/farmacologia , Mastócitos/metabolismo , Ratos WistarRESUMO
The direct effect of ethanolic extract of propolis on guinea pig lung cell suspension containing mast cells, as well as its influence on the histamine release induced by antigen (ovoalbumin 10 mug/ml) and ionophore A 23187 (3 muM) were investigated. Propolis ethanolic extract (300 mug/ml) increased the histamine release in guinea pig lung suspension containing mast cells by a cytotoxic effect. Lower concentrations of propolis had no effect on histamine release. Our results demonstrated that propolis (3, 10, 30, and 100 mug/ml) shows no significant effect on the histamine release induced by ionophore and antigen. Based on these results, we suggest that propolis could directly activate mast cells, promoting inflammatory mediators release by cytotoxic mechanisms, what could be related to allergic processes in propolis sensitive people.(AU)
Assuntos
Própole , Histamina , Mastócitos , CitotoxinasRESUMO
This study was carried out to evaluate the relationship of abomasal inflammatory cells and parasite-specific immunoglobulin A (IgA) in mucus, with the resistance to Haemonchus contortus infection in three breeds of sheep naturally infected with gastrointestinal nematodes. The breeds were the native Santa Ines sheep, and the European Suffolk and Ile de France breeds. Mast cells, eosinophils and globule leucocytes were enumerated in abomasal mucosa. Eosinophils within the sub-mucosa also were counted separately. Histamine concentration was estimated in abomasal tissue samples. Enzyme-linked immunosorbent assay was carried out in mucus samples to determine the level of IgA anti-H. contortus third and fifth instar. There were no significant differences among group means of these variables (P>0.05). The correlation coefficients between fecal egg counts (FEC)xmast cells (r=-0.490; P<0.05) and FECxeosinophils in sub-mucosa (r=-0.714; P<0.01) was significant in the Santa Ines sheep. In the Ile de France group, the correlation coefficients between globule leucocytesxFEC (r=-0.879; P<0.001) and histaminexworm burden (r=-0.833; P<0.01) were also significant. In the Santa Ines and Ile de France sheep, correlation coefficients between IgA anti-L3xworm burden and IgA anti-L3xFEC were negative. In general, inflammatory cells and IgA-parasite-specific in abomasum were inversely associated with H. contortus worm burden and FEC indicating that they may impair parasite development or fecundity in the three breeds of sheep. However, similar mean values of inflammatory cells and IgA were found in the resistant (Santa Ines) and in the susceptible (Suffolk and Ile de France) breeds of sheep. The enumeration of cells by histological assessment does not provide information on their functional activity, which may be different among breeds. Thus, the effect of breed on the functional activity of these and other inflammatory cells is an important area for further study.
Assuntos
Abomaso/parasitologia , Gastroenteropatias/parasitologia , Hemoncose/veterinária , Haemonchus/imunologia , Imunoglobulina A/imunologia , Doenças dos Ovinos/parasitologia , Abomaso/imunologia , Animais , Anticorpos Anti-Helmínticos/análise , Especificidade de Anticorpos , Ensaio de Imunoadsorção Enzimática/veterinária , Eosinófilos/imunologia , Eosinófilos/parasitologia , Fezes/parasitologia , Mucosa Gástrica/imunologia , Mucosa Gástrica/parasitologia , Gastroenteropatias/imunologia , Hemoncose/imunologia , Hemoncose/parasitologia , Histamina/imunologia , Leucócitos/imunologia , Leucócitos/parasitologia , Mastócitos/imunologia , Mastócitos/parasitologia , Contagem de Ovos de Parasitas/veterinária , Ovinos , Doenças dos Ovinos/imunologia , Estatísticas não ParamétricasRESUMO
This study was designed to evaluate the toxicogenetic or protective effect of cooked and dehydrated black beans (Phaseolus vulgaris L.) in bone marrow and peripheral blood cells of exposed mice. The frequency of micronuclei detected using the bone marrow erythrocyte micronucleus test and level of DNA lesions detected by the comet assay were chosen as end-points reflecting mutagenic and genotoxic damage, respectively. Initially, Swiss male mice were fed with a 20% black bean diet in order to detect mutagenic and genotoxic activity. However, no increase in the frequency of bone marrow micronucleated polychromatic erythrocytes (MN PCEs) or DNA lesion in leukocytes was observed. In contrast, received diets containing 1, 10 or 20% of black beans, a clear, but not dose-dependent reduction in the frequency of MN PCEs were observed in animals simultaneously treated with cyclophosphamide, an indirect acting mutagen. Similar results were observed in leukocytes by the comet assay. Commercial anthocyanin was also tested in an attempt to identify the bean components responsible for this protective effect. However, instead of being protective, the flavonoid, at the highest dose administered (50 mg/kg bw), induced primary DNA lesion, as detected by the comet assay. These data indicate the importance of food components in preventing genetic damage induced by chemical mutagens, and also reinforce the role of toxicogenetic techniques in protecting human health.