A systemic approach to the oral problem of mandibular resorption

It is argued that mandibular resorption can be considered as osteoporotic in nature. This calls for a systemic approach in its treatment. One aspect mostly neglected is the tendency of bone to bind calcium and phosphate ions. A direct measure for this tendency is the difference in pH between the bone extracellular fluid and blood plasma. This pH difference is directly reflected by the degree of saturation of blood plasma with octocalcium phosphate. Calculation of these degrees of saturation of about 2000 data of blood plasma compositions given in the literature indicates that calcitonin injection, estrogen replacement and magnesium supplementation increase the tendency of bone to bind calcium and phosphate ions and hence should be used in the therapy of mandibular resorption and of bone resorption in general.Il est prouvé que la résorption mandibulaire peut être considérée comme étant de nature ostéoporotique.Ceci veut dire que le traitement doit être systémique. L’un des aspects souvent négligés est la tendance qu’a l’os à fixer les ions calcium et phosphate. Une mesure directe de cette tendance est obtenue par la difference de pH entre le fluide extracellulaire de l’os et le plasma sanguin. Cette différence de pH est directement révélée par le degré de saturation du plasma sanguin par rapport au phosphate octocalcique. Le calcul de ce degré de saturation sur environ 2000 données de compositions plasmatiques fournies dans la littérature indiquent que des injections de calcitonine, l’équilibration en oestrogènes et un apport de magnésium augmentent la tendance de l’os à fixer les ions calcium et phophate et, par conséquent, devraient être utilisés pour la thérapie de la résorption mandibulaire et de la résorption osseuse en général

Aspects of harmonisation of individual monitoring for external radiation in Europe: Conclusions of a EURADOS action

Following the publication of the EU Council Directive 96/29, EURADOS coordinated two working groups (WGs) for promoting the process of harmonisation on individual monitoring of occupationally exposed persons in Europe. An overview of the major findings of the second WG is presented. Information on the technical and quality standards and on the accreditation and approval procedures has been compiled. The catalogue of dosimetric services has been updated and extended. An overview of national regulations and standards for protection from radon and other natural sources in workplaces has been made, attempting to combine the results from individual monitoring for external, internal and workplace monitoring. A first status description of the active personal dosemeters, including legislative and technical information, and their implementation has been made. The importance of practical factors on the uncertainty in the dose measurement has been estimated. Even if a big progress has been made towards harmonisation, there is still work to be don

The effect of undissociated acetic-acid concentration of buffer solutions on artificial caries-like lesion formation in human tooth enamel

A chemical system for lesion production was used. The influence on lesion characteristics of the concentration of undissociated acetic acid in a calcium and phosphate-containing buffer solution was investigated. Artificial lesions obtained after demineralization in buffers with a pH of 4.0, 4.5, 5.0 or 6.0 at 5 or 6 different acid concentrations for different demineralization times were investigated microradiographically. The lesion characteristics studied were: (a) the mineral content of the surface layer; (b) the mineral content of the body of the lesion; (c) and (d) the depth at which these mineral levels were reached; (e) the depth of the lesion. The concentration of undissociated acetic acid had little effect on the lesion characteristics at low pH. When lower concentration buffers at pH 6.0 were used, the effect was more pronounced. At this level, the buffer capacity of the acetic acid/acetate buffer is small