47 research outputs found

    Comparison of the effect of different surface treatments on the bond strength of different cements with nickel chromium metal alloy : an in vitro study

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    For success of any indirect metal restoration, a strong bond between cement and the intaglio surface of metal is imperative. The aim of this study is to evaluate and compare the effect of different surface treatment on the tensile and shear bond strength of different cements with nickel?chromium alloy. 120 premolars were sectioned horizontally parallel to the occlusal surface to expose the dentin. Wax patterns were fabricated for individual tooth followed by casting them in nickel chromium alloy. 60 samples were tested for tensile bond strength, and the remaining 60 for shear bond strength. The samples were divided into three groups (of 20 samples each) as per the following surface treatment: oxidation only, oxidation and sandblasting, or oxidation, sandblasting followed by application of alloy primer. Each group was subdivided into 2 subgroups of 10 samples each, according to the bonding cement i.e RM-GIC and resin cement. Samples were subjected to thermocycling procedure followed by evaluation of bond strength. Two-way analyses of variance (ANOVA) was performed to compare the means of tensile and shear bond strength across type of surface treatment and cement, followed by post hoc parametric analysis. For all tests ?p? value of less than 0.05 was considered statistically significant. The surface treatment of oxidation and sandblasting followed by application of alloy primer offered the maximum tensile and shear bond strength for both RM GIC and resin cement. Resin cement exhibited greater tensile and shear bond strength than RM-GIC for all the three surface treatment methods

    A Comparative Analytical Study of Krishna Musali Choorna and Krishna Musali Kshara

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    Krishna Musali (Curculigo orchioides) is among the Dashapushpa, a group of ten herbs which is culturally and medically important to the people of Southern India, especially in Kerala. Krishna Musali is mentioned in various context in the names of Krishna Musali, Talapatri, Talamooli etc. and it is having Madhuratikta rasa, Ushna virya and it is Vatapittahara and Rasayana properties. In classics references about this drug can be seen in the context of Dhoomapana yoga, Kshara vidhi, Ekangasopha chikitisa etc and the Acharyas were categorized in to specific Gana or Varga based on its mode of action.  Krishna Musali Choorna and Kshara prepared based on the method of preparation mentioned in Sharangadhara Samhita. Analytical study was carried out for the purpose of standardization. For the qualitative assurance of the raw material analytical study provides the objective parameters for the standardization leading to a reproducible quality. These tests were done for evaluating the anticancer activity of Krishna Musali Choorna and Kshara in cervical cancer cell lines. The preliminary phytochemical study shows high alkalinity of Krishna Musali Kshara compared to Choorna, it supports the definition of alkali of being caustic and corrosive in nature. So, it will be helpful in the treatment of early stages of Cervical carcinoma

    Effect of conventional and microwave glazing on surface roughness of metal ceramics: An atomic force microscopy analysis

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    Purpose: This study investigated and compared the surface roughness achieved by glazing porcelain samples in a conventional and a microwave oven. Materials and Methods: Two commercial brands of metal ceramics were used, VITA VMK MASTER and IPS CLASSIC. Sixty samples were fabricated, 30 for each type of ceramic. The samples were sintered in the conventional oven and hand-polished to remove any irregularities. Samples (n = 10) from each type of ceramic were further divided into three groups as follows: hand-polished (Group A), conventional oven glazed (Group B), and microwave glazed (Group C). Each specimen was evaluated for surface roughness by atomic force microscope. Data were statistically analyzed using two-way analysis of variance (ANOVA) and Tukey's post hoc test (a = 0.05). Results: Two-way ANOVA indicated a highly significant difference in surface roughness based on the type of glazing (P < 0.001), there was a significant difference based on the metal ceramics (P = 0.002). There was also a significant interaction between the type of glazing and metal ceramics (P = 0.009). The images obtained from the atomic force microscope corroborated the measured values. Conclusions: All the results indicate that microwave glazing can be a feasible option for glazing porcelain specimens. It was concluded that surface topography is influenced by surface treatment and microwave glazed ceramic is superior to conventional oven glazed ceramic and hand-polishing showed greater surface roughness when compared to glazing. IPS CLASSIC ceramic showed relatively smooth surface when compared to VITA VMK MASTER irrespective of the surface treatment

    Prosthetic rehabilitation of hemimandibulectomy defect with removable partial denture prosthesis using an attachment-retained guiding flange

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    The restoration of normal function and esthetics is often challenging in the prosthetic rehabilitation of patients with hemimandibulectomy defects due to unstable occlusion and mandibular deviation. The extensive period of time for completion of healing of the reconstructed mandible through reconstructive plastic surgery and/or implant-assisted prosthesis may compromise the masticatory function by causing delay in the fabrication of definitive prosthesis. This case report describes a novel technique for the construction of customized attachment-retained mandibular guiding flange prosthesis for immediate rectification of the frontal plane rotation occurring after hemimandibulectomy

    Gastrointestinal Delivery of Baculovirus Displaying Influenza Virus Hemagglutinin Protects Mice against Heterologous H5N1 Infection▿

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    The recent outbreaks of influenza A H5N1 virus in birds and humans have necessitated the development of potent H5N1 vaccines. In this study, we evaluated the protective potential of an immediate-early promoter-based baculovirus displaying hemagglutinin (BacHA) against highly pathogenic avian influenza (HPAI) H5N1 virus infection in a mouse model. Gastrointestinal delivery of BacHA significantly enhanced the systemic immune response in terms of HA-specific serum IgG and hemagglutination inhibition (HI) titers. In addition, BacHA vaccine was able to significantly enhance the mucosal IgA level. The inclusion of recombinant cholera toxin B subunit as a mucosal adjuvant along with BacHA vaccine did not influence either the systemic or mucosal immunity. Interestingly, an inactivated form of BacHA was able to induce only a negligible level of immune responses compared to its live counterpart. Microneutralization assay also indicated that live BacHA vaccine was able to induce strong cross-clade neutralization against heterologous H5N1 strains (clade 1.0, clade 2.1, and clade 8.0) compared to the inactivated BacHA. Viral challenge studies showed that live BacHA was able to provide 100% protection against 5 50% mouse lethal doses (MLD50) of homologous (clade 2.1) and heterologous (clade 1) H5N1. Moreover, histopathological examinations revealed that mice vaccinated with live BacHA had only minimal bronchitis in lungs and regained their body weight more rapidly postchallenge. Furthermore, immunohistochemistry results demonstrated that the live BacHA was able to transduce and express HA in the intestinal epithelial cells in vitro and in vivo. We have demonstrated that recombinant baculovirus with a white spot syndrome virus (WSSV) immediate-early promoter 1 (ie1) acted as a vector as well as a protein vaccine and will enable the rapid production of prepandemic and pandemic vaccines without any biosafety concerns

    Synthesis, Structure, and Transformation Studies in a Family of Inorganic-Organic Hybrid Framework Structures Based on Indium

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    Eight new open-framework inorganic-organic hybrid compounds based on indium have been synthesized employing hydrothermal methods. All of the compounds have InO6, C2O4, and HPO3/HPO4/SO4 units connected to form structures of different dimensionality Thus, the compounds have zero- (I), two- (II, III, IV, V, VII, and VIII), and three-dimensionally (VI) extended networks. The formation of the first zero-dimensional hybrid compound is noteworthy In addition, concomitant polymorphic structures have been observed in the present study. The molecular compound, I, was found to be reactive, and the transformation studies in the presence of a base (pyridine) give rise to the polymorphic structures of II and III, while the addition of an acid (H3PO3) gives rise to a new indium phosphite with a pillared layer structure (T1). Preliminary density functional theory calculations suggest that the stabilities of the polymorphs are different, with one of the forms (II) being preferred over the other, which is consistent with the observed experimental behavior. The oxalate units perform more than one role in the present structures. Thus, the oxalate units connect two In centers to satisfy the coordination requirements as well as to achieve charge balance in compounds II, IV, and VI. The terminal oxalate units observed in compounds I, IV, and V suggest the possibility of intermediate structures. Both in-plane and out-of-plane connectivity of the oxalate units were observed in compound VI. The 31 compounds have been characterized by powder X-ray diffraction, IR spectroscopy, thermogravimetric analysis, and P-31 NMR studies
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