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Biomedical subjects

P L Fan

Publications and source records attributed to P L Fan.

67 records · Page 4Linked to original sources

Properties of microfilled and visible light-cured composite resins.

Physical and mechanical properties of four commercial micro-filled composite resins, a visible light-cured composite resin, and a conventional composite resin were investigated. Isocap, Isopast, and Superfil were similar in most properties. Compared with Concise, they had lower values of inorganic filler content and modulus of elasticity and higher values of water sorption, depth of indentation, and linear coefficient of thermal expansion. The properties of Silar were between those of Concise and the other microfilled composite resins. Fotofil had lower values of modulus of elasticity, water sorption, and linear coefficient of thermal expansion than Concise.

Absorption↗

Effect of hydrostatic tensile stress on the growth of Escherichia coli and Bacillus cereus.

The specific growth rates of Escherichia coli and Bacillus cereus were measured for growth media in a flask, a lens-plate arrangement simulating an isolated capillary space, and a lens-plate arrangement under hydrostatic tensile stress. The specific growth rates of the bacteria were the same for the flask and lens-plate arrangement without hydrostatic tensile stress, but were enhanced when the growth media were subjected to hydrostatic tensile stress. The enhanced specific growth rates reached steady values at a tensile stress of 40 pascals. The effect was observed up to tensile stresses of around 100 pascals. The maximum increase in specific growth rate was 25% for E. coli and 22% for B. cereus.

Bacillus cereus↗

Penetrativity of sealants: I.

Penetration coefficients of sealants were measured. It was found that the time required for a sealant to penetrate a specific distance is highly dependent on the penetration coefficient of the sealant.

Capillary Action↗

Color differences coefficients of body-opaque double layers.

Porcelain restorations have double-layer color effects resulting from the presence of body and opaque layers. The purpose of this study was to quantify the color differences resulting when a defined thickness of body porcelain is fired on an opaque porcelain of the same shade designation and from the same porcelain brand. A color difference coefficient was defined as the color change resulting from a 1-mm-thick layer of body porcelain on an opaque porcelain of the same shade and brand. Six shades and four porcelain brands were evaluated in this study. The range of color difference coefficients for all shades and brands was 6.76 to 14.32. There was no significant difference between shades or between brands. The use of color difference coefficients is a practical method of evaluating porcelain shades and brands and should provide guidance in the choice of porcelains and the fabrication of porcelain restorations to better achieve the desired esthetics.

Color↗