Periodontal status of teeth with crown-root fractures: results two years after adhesive fragment reattachment.

Aim: This series of case reports evaluated the impact of adhesive crown-root fragment reattachment in periodontally healthy teeth suffering from crown-root fractures on various parameters of periodontal health over a time course of 2 years.

Material And Methods: A total of 20 teeth with crown-root fractures in 18 periodontally healthy subjects were evaluated. After open-flap access, crown-root fragments were adhesively reattached to the root stub.

The influence of plasma arc vs. halogen standard or soft-start irradiation on polymerization shrinkage kinetics of polymer matrix composites.

Objectives: To determine polymerization shrinkage kinetics and hardness of photo-activated polymer matrix composites (PMC) after plasma arc vs. halogen standard or soft-start irradiation.

Methods: Polymerization shrinkage was measured using the 'deflecting disk technique', and Knoop hardness was measured at the bottom of 1.

Ammonia caramels: specifications and analysis.

Twenty three UK commercially produced ammonia caramels and eight experimentally produced ammonia caramels have been analysed by a range of physical and chemical tests, which include solids content, nitrogen levels, colour intensity and pH. A statistical treatment of the results is reported.

Colourings and preservatives in food.

Colours and preservatives are only two of the many classes of additives in food but they are of interest because many reported cases of sensitivity involve these two groups of substances. Preservatives present the greatest potential health hazard being, by definition, biologically active. Colours and other additives are required to perform a technological function whilst remaining as biologically inert as possible.

Adaption of a diamond anvil cell to an automatic four-circle diffractometer for x-ray diffraction.

A diamond anvil high-pressure device for x-ray diffraction on single crystals under hydrostatic pressures up to about 100 kilobars has been adapted to the automatic four-circle x-ray diffractometer Philips PW 1100. The mechanical adaption, the centering procedure, and quick pressure calibration on the diffractometer are described. Hints to improve the peak-to-background ratio of the intensity measurements are given.

Thermal stratification in the arctic ocean.

Fine scale measurements of the vertical temperature profile in an Arctic water column show the presence of several cascaded isothermal layers. Layers between the depths of 300 anid 350 meters range from 2 to 10 meters in thickness, while the temperature change between adjacent layers is approximately 0.026 degrees C.

The metabolism of potassium dodecyl [35-S]sulphate in the rat.

The metabolic fate of potassium dodecyl [(35)S]sulphate was studied in rats. Intraperitoneal and oral administration of the ester into free-ranging animals were followed by the excretion of the bulk of the radioactivity in the urine within 12hr., approximately 17% being eliminated as inorganic [(35)S]sulphate.