A study on the evolution with age of the mineral composition of bones
was performed on samples belonging to human and other common mammalian
species (cattle, sheep, dog). The study was carried out on the ashes
obtained by calcination of the bone samples (1 h at 900 degrees C). Th
e calcined powders were carefully examined by X-ray diffraction, from
which precise quantitative evaluation (also confirmed by chemical anal
ysis) of the crystalline phases present was derived. These data were a
nalysed as a function of the introduced fractional age Phi, a new rela
tive scale that allows even largely different lifespan species to be c
ompared. An overall linear increase in (Ca + Mg)/P ratio with log Phi
was found and the other considerations on molecular constitution (espe
cially as regards Mg2+ substituting for Ca2+ in very young subjects) o
f the various phases detected were formulated and relative implication
s evaluated. The results appear promising for an improvement of knowle
dge in the field of biomedical experimentation and clinical implantolo
gy.