IN-VIVO AND IN-VITRO CHANGES IN STRENGTH OF ORTHOPEDIC CALCIUM ALUMINATES

Calcium aluminate bars are formulatad to study the effect of real and simulated biologic environments on strength. Static fatigue tests reveal that the strength of these potential internal bone prostheses decreases to ca. 60% of their initial strength after less than 100 min while being held at constant stress in solution. Calcium aluminate bars aged for 12 weeks in water or Ringer solution are also found to exhibit large losses in strength, while bars implanted in vivo for the same period of time weakened somewhat less.