Incorporation of particulated bone implants in the facial skeleton

The purpose of this study was to compare the regenerative response of autog enous cortical and cancellous bone chips and a natural particulate resorbab le bone mineral (RBM) (Bio-Oss(R), Geistlich-Pharma, Wolhusen, Switzerland) in standardized bony defects relating paranasal sinuses to one another and to bone blocks. On 13 skeletally mature female goats four standardized cri tical-sized full thickness bone defects were made in the frontal bone overl ying the frontal sinus. These defects were filled at random with cortical b one chips, cancellous bone chips, spongiosa granules of a RBM or left empty . Fluorochrome bone markers were injected subcutaneously 1 and 5 weeks afte r transplantation, and one week before the animals were killed. The animals were killed at 3, 6, 12 and 24 weeks after surgery. Autogenous cancellous bone chips is the material of choice for bridging a bony defect in the maxi llofacial area where there is no need for mechanical strength. They heal in the same way as cancellous bone blocks do. Cortical bone chips are not rel iable enough to be used as a solitary bone-grafting material under these co nditions. A cortical block as a solitary implant gives better results. RBM granules as solitary implant in a critical-sized defect do not stimulate os teoconduction but give rise to an extensive osteoclastic activity stimulate d by the mutual loose relation. A solid block of RBM is in a similar case m ore reliable. (C) 1999 Elsevier Science Ltd. All rights reserved.