ASSESSMENT OF BONE SURROUNDING IMPLANTS IN GOATS - EX-VIVO MEASUREMENTS BY DUAL X-RAY ABSORPTIOMETRY

The aim of the present study is to determine the possibility of measur ing the bone mineral density (BMD) around implants by dual energy X-ra y absorptiometry (DEXA). Therefore, the trabecular BMD was measured cl ose to 127-600 mu m and at a distance from various uncoated and Ca-P-c oated implants inserted into the femoral condyle of goats. The implant s were left in situ for 12 weeks. In addition, the bone-implant interf ace was evaluated histologically. For comparative reasons the BMD of n onimplanted lateral and medial femoral condyles was also measured. The reproducibility of the measurements, expressed as a coefficient of va riation, was found to be 0.44%. Moreover, the regions closest to the i mplants exhibited a higher BMD than all other regions, and the regions located in the medial condyle showed a higher BMD than the lateral co ndylar regions. Although the histological sections of the implants in the medial condyle demonstrated more bone contact with the coated than with the uncoated implants, a higher density was measured around the uncoated implants. The results regarding the non-implanted condyles in dicated a higher density in the medial than in the lateral condyle. In view of these results, we conclude that BMD around dental implants de pends on the location of the implant and that DEXA appears to be an ex cellent tool for analysing bone-implant reactions. (C) 1997 Elsevier S cience Limited.