Browsing by Author "Nair, EKP"

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    Bonding agent is a decisive factor in determining the marginal leakage of dental composites subjected to thermal cycling: an in vitro study
    (JOURNAL OF ORAL REHABILITATION, 2001) Mathew, M; Nair, EKP; Krishnan, K
    The marginal leakage at the dentine/composite interface in Class II composite restorations subjected to thermal cycling has been effectively evaluated using the silver staining technique. The presence of a bonding agent at the dentine/composite interface is found to improve adhesion. Scanning electron and optical microscopic observations of sectioned specimens reveal that applying a second coat of bonding agent on the dentinal surface helps in reducing microleakage compared to a single coat application, in all three radiopaque composite/bonding agent systems studied (Z1001Single Bond, Spectrum TPH/Prime & Bond 2.1 and Chitra/Chitrabond 1.0). Thermal cycling during in vitro studies was found to provide a more appropriate representation of the adhesive behaviour of the composite in clinical situations.
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    Shear bond strength evaluation of five bonding agents in combination with three radiopaque composites on wet/dry dentine surfaces: An in vitro study
    (CURRENT SCIENCE, 2000) Koshy, S; Nair, EKP; Krishnan, VK
    Shear bond strength of five dentine bonding agents in combination with three radiopaque composites on dry and wet dentinal surfaces was evaluated in this study. Human premolar teeth mounted on acrylic resin were sectioned to expose dentinal surfaces onto which composites were fixed using a bonding agent. An observation of the shear strengths obtained from 36 composite/bonding agent combinations on dry/wet dentinal surfaces revealed no dentine adhesion for composites in the absence of a bonding agent. Adhesion using a bonding agent was found to enhance shear strength values to varying extents depending on the composite/bonding agent system used and the nature of the dentinal surface. Bond strengths were found to be higher on wet than dry dentinal surfaces though this was found to depend to a large extent upon the nature of the composite and/or bonding agent system used. In certain cases, combination systems other than recommended ones were found to provide better strength values. This study shows that shear bond strength depends not only on the nature of the dentinal surface but also is specific of the composite/bonding agent system used, thus providing an insight into their apparent clinical behaviour.