Effects of direct currents on bone growth into delrin implants

The delrin Bone Growth Chamber (BGC) which is a dividable implant, was inserted in its assembled form in the tibial metaphysis of the rabbit. The BGC allows a numerical estimation of the bone growth into the implant, based on microradiography and microdensitometry that permits evaluation of direct current (DC) effects on bone regeneration. A test chamber was inserted in one tibia and was stimulated with either 5, 20 or 50 microA for three weeks, while on the contralateral side of the same animal, a control implant was inserted under identical conditions as the test, but was not stimulated. The results showed a significant increase of bone growth with 20 and 50 microA and a tendency towards more bone formation with 5 microA.