Are there any limits to the dental treatment of children?

AIM: The objective of this paper is to describe and discuss the most commonly occurring limits in care provision between a dentist and a child, i.e. provider and recipient. METHODS: The study was conducted online in the form of an anonymous questionnaire survey. We were looking for dentists to answer two basic modeled situations during the treatment of deciduous teeth (filling and extraction) in 4-year-old and 8-year-old children. Each modeled situation had 9 possible clinical scenarios. The age was chosen to factor the cooperation of a preschool- and a school-age child. CONCLUSION: The experience gained through clinical practice and the number of treated children show to be fundamental for the treatment of child's deciduous teeth and for the selection of a treatment method. Dentists acquire sufficient knowledge through their education in the faculties of medicine. The limit is the child itself, therefore it is desirable to build specialised centres for their treatment.

Natural inactivation of phosphorus by aluminum in atmospherically acidified water bodies.

Atmospheric acidification of catchment-lake ecosystems may provide natural conditions for the in-lake control of P cycling. This process is based on the elevated transport of aluminum from acidified soils and its subsequent precipitation in the water body and is described for strongly acidified forest lakes, acidified and circumneutral reservoirs, and a moderately acidified alpine lake. In water bodies with episodically or permanently acidified inflows a pH gradient develops between lake water and tributaries due to: (i) neutralization of acidic inflows after mixing with waters with undepleted carbonate buffering system, and/or (ii) the in-lake alkalinity generation dominated by biochemical removal of NO3- and SO4(2-). With the pH increasing towards neutrality, ionic Al species hydrolyze and form colloidal Al hydroxides (Al(part)) with large specific surfaces and strong ability to bind orthophosphate from the liquid phase. Moreover, Alpart settles and increases the P sorption capacity of the sediment. The presence of Al(part) on the bottom reduces orthophosphate release from sediments after its liberation from ferric oxyhydroxides during anoxia because Al(part) is not sensitive to redox changes. Consequently, the natural in-lake P inactivation may be expected in any water body with elevated Al input and a pH gradient between its inlet and outlet.

Changes in incidence of carcinoma in situ after the Chernobyl disaster in central Europe.

The data files from an extensive cytological screening program for cervical intraepithelial neoplasia from a regional Czech hospital were analyzed. The data collection span is from 1985 to 1991 and shows highly significant maximum effects in the years 1988-1989, i.e., shortly after the Chernobyl accident. The increase was concordantly found in all the age categories, but the reaction seems to be faster in younger women. The delayed maximum effect (two years after the accident) also corresponds to the course of total foodstuffs burden and total-body activity.