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

X-ray diffraction of enamel of a freshly erupted human tooth

No abstract availabl

Diffusion inhibition as a mechanism for the caries-reducing effect of fluoride

One of the mechanisms proposed for the caries-reducing effect of fluoride is diffusion inhibition of OH–– groups through the 63 columns of the apatite structure thereby increasing the resistance of the crystal against acidic attack. The validity of this hypothesis was checked by investigation of the reactivity of solid solutions of hydroxyapatite and oxyapatite for oxydation during storage for 3 years in air. These solid solutions provide the same number of vacancies in the OH positions as occur in the apatite of tooth enamel, whereas the mobility of the OH–– ions is the critical quantity for its reactivity in analogy with fluorhydroxyapatite solid solutions. It was found that the solid solutions were not oxydized as their lattice parameters did not change during the storage period although the experimental period was far within the limits of the theoretical estimate. This invalidates the proposed mechanism for the caries-reducing effect of fluoride, as it proves the solid state diffusion is not important in apatites at normal temperatures

X-ray diffraction of enamel of a freshly erupted human tooth

No abstract availabl

X-ray diffraction of enamel of a freshly erupted human tooth

No abstract availabl