THE IMMEDIATE EFFECTS OF IONOMERIC AND ACRYLIC BONE CEMENTS ON PERIPHERAL-NERVE FUNCTION

A total of 44 rat saphenous nerves were isolated. A pair of stimulatin g electrodes was positioned distally (at the ankle) to evoke a compoun d action potential (CAP) which was recorded proximally (in the thigh) through another pair of electrodes. Bone cement was then placed adjace nt to the nerve midway between the electrodes and changes in the CAP r ecorded over a 30-min period. Nerve conduction was completely blocked within 2 min of placing unset acrylic bone cement adjacent to the nerv e. The experimental ionomeric cements (IC) also caused a reduction in the nerve conduction although this did not usually occur until the cem ent had been positioned adjacent to the nerve for over 10 min. Slow-se tting IC blocked nerve conduction more quickly than fast-setting IC bu t there was no apparant difference between the effects of applying mat erials early or late in the setting reaction. Set ionomeric porous mic roimplant particles (lonogran(R)) had no effect on neural function.