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Biomedical subjects

M R Lund

Publications and source records attributed to M R Lund.

At least 19 recordsLinked to original sources
PubMed1990

Color stability of composite resins.

The color stability of seven visible light-cured and three chemically-cured composite resins was investigated while being subjected to UV light irradiation and storage in an aqueous environment at elevated temperatures. Color shift was evaluated visually and by colorimetric measurements. Significant correlation was found between visual scoring and colorimetric readings. When subjected to UV light, a wide deviation in color change existed from brand to brand in photocured composite resins. The color shift of chemically-cured composite resins was less than but fell within the range of photocured composite resins. When stored in water at elevated temperatures, photocured resins exhibited better color stability than the chemically-cured composite resins.

Chemical Phenomena↗
PubMed1989

Retentive pin systems: a laboratory comparison of effectiveness of seating and other characteristics.

An evaluation in vitro of a number of currently available pin systems used for retaining direct restorative materials was made in this study. The criteria used for evaluation of the systems were completeness of pin seating in the prepared channels and overall effectiveness of the design of the shoulder-stop-style pins. There was a wide range of difference in the ability to seat pins completely, and the seating of the shoulder-stops on the dentin floor was quite inconsistent.

Dental Pins↗
PubMed1979

Retention of dowels subjected to tensile and torsional forces.

This investigation measured the maximal tensile and torsional forces sustained by four different designs of dowels. 1. Under tensile force, the threaded screw-in dowels were significantly more retentive than the unthreaded dowels. 2. Under torque, both the threaded screw-in and serrated dowels were significantly more retentive than the smooth-sided dowels.

Crowns↗
PubMed1977

Recrystallization of compacted gold foil specimens.

Gold foil specimens were compacted by a technique commonly used in preparing dental restorations. Their recrystallization behavior for temperatures between 100 and 300 C was followed by the associated decrease in hardness, discontinuous increase in grain size, and disappearance of X-ray line broadening. The empirical dependence of time, t, (in minutes) for 50% recrystallization on annealing temperature (in K), T, is approximately log10 t=-12.3+6.5X1,000/T, indicating a recrystallization time greater than 100 years.

Crystallization↗