A 36-item questionnaire was used to investigate the stress perceived by students at Manchester Dental School to potential stressors, grouped under the headings of living accommodation, personal factors, educational environment, academic work and clinical factors. The stressors producing the highest ratings for perceived stress varied throughout the course but high values were allocated to examinations, fear of failing the course or year, shorter and fewer holidays than other university students and--for clinical students--approachability of staff and completing the required quantity and variety of work within a limited time. Female students experienced greater stress than their male counterparts. Since high levels of perceived stress can reduce student performance, dental schools should consider courses in stress management.

The procedure developed in this investigation is suitable for determining the abrasion resistance of restorative materials to toothbrush/dentifrice abrasion. Ideally, a restoration should have an abrasion resistance similar to that of enamel. Of the materials tested, gold was the only one that wore slightly less than enamel, whilst amalgam wore almost twice as quickly. The silicate material and composites (excluding TD.71) wear away 2-4 times faster than enamel. TD.71 and especially the unfilled resin exhibited very high rates of abrasion. After prolonged toothbrush/dentifrice abrasion, the surfaces of gold and amalgam were considerably smoother than those of the silicate and composite materials.

The sustainability of natural resource use is influenced by population pressure, but this exercises a much less critical impact than the overall policy framework. In Colombia, various agricultural and other policies whose effect is to constrain the poor's access to land encourage environmental degradation. A case is made in favour of the new land reform process that Colombia is launching.

A clinically realistic in vitro study was performed to determine the best method for smoothing trimmed surfaces of seven composite restorative materials. Soflex discs produced the smoothest surface, and little advantage appeared to be gained by prior smoothing of the surface with stones or points. A polishing paste, even when used with intermediate finishing agents, produced a rougher surface than that left by the discs.