Effect of external stresses on calcium phosphate glass investigated by IR spectroscopy.

Abstract

The effect of external stress on calcium phos- phate glasses was investigated because they experience high stress in practical uses such as mastication. In order to un- derstand the structural change of calcium phosphate glasses caused by an applied stress, the IR reflection peak shift of the phosphate structural band of the calcium phosphate glass fiber due to a bending stress was measured. The peak shift represents the change of the P-O-P bond angle. The IR reflection peak of the phosphate structural bands near ~1300 and ~910 cm ˛1 shifted to a higher wavenumber under tensile stress and to a lower wavenumber under compressive stress when calcium phosphate fiber with a uniform structure was employed. This indicates that the P-O-P bond angle in- creases under tensile stress and decreases under compres- sive stress. The extents of both peak shifts were larger with a higher Ca/P ratio than with a lower Ca/P ratio. Therefore, phosphate glass with a higher Ca/P ratio is expected to withstand loads under external stress. © 2000 John Wiley & Sons, Inc. J Biomed Mater Res, 49, 233-237, 2000.