Electron probe microanalysis of human teeth for the determination of individual age

The calcium and phosphorus weight concentrations as well as the calcium/phosphorus weight ratio were determined by electron probe microanalysis both peritubularly and intertubularly in the dentine of 25 adults of varying age and sex, originating from our autopsy material. The studies were performed with a TESLA BS-300 scanning electron microscope coupled with an EDAX-149-10 X-ray detector and a BMG-38100 X-ray analyser with an accelerating potential of 15 kV, a sample current of 100 pA and a measurement time of 20 s. Peritubularly the Ca/P weight ratio of the hypermineralized part of the dentine decreases with age and is in close correlation with it (r = -0.9052) and this tendency is significant even at the level of 95% (P less than 0.05). The equation of the regression line is: Y = 37.17 x +139.37 where x is the age and y is the Ca/P weight ratio. The weight concentration of phosphorus is in an even closer correlation with age (r = 0.9712) and this correlation is also significant (P less than 0.01). The equation of the regression line is the following: y = 625.0 x -42.06 The close correlation of both the Ca/P weight ratio of the teeth and of the phosphorus weight concentration with the age allows individual age determination to be performed in the course of forensic medical and palaeoanthropological studies.