Zinc sulfate calcium phosphate (ZSCAP) composite for repairing traumatized bone

The objective of this investigation was to evaluate the suitability of zinc sulfate calcium phosphate ceramic composites as bone substitutes. ZSCAP ceramics were fabricated from stock powders of zinc sulfate, zinc oxide, calcium oxide, and phosphorous pentoxide in a ratio of 15:30:30:25 by weight of ZnSo4:ZnO:CaO:P2O5. The three oxides and zinc sulfate were mixed for 10 minutes in a blender and then calcined in a crucible at 650 degrees C for 24 hours. The calcined powder was ground in a ball mill for 0.5 hours and separated into particle sizes of 38-45, 45-63, and 65-75 microns by an automatic siever and shaker. One hundred male, albino, Sprague-Dawley rats, weighing 250-300 g each, were used to conduct the investigation. The treatments (10 rats per treatment) were as follows: Group I, non-operated controls, Group II, sham-operated controls, and Groups III, IV and V, experimental animals. In situ hardening ZSCAP ceramic particulate powders or pastes of 38-45 microns (Group III), 45-63 microns (Group IV) or 65-75 microns (Group V) were implanted in a 2.0 mm defect in the femur of each rat. Radiographic and morphologic examination of the implant site indicated that the implant was biocompatible and firmly entrenched in the traumatized bone defect up to 90 days post-implantation. Since ZSCAP ceramics set like plaster of Paris and have all the beneficial properties of resorbable calcium phosphate, they should provide the surgeon with a non-toxic, resorbable, fast setting ceramic (in situ) for use as a hard tissue substitute in orthopaedic, dental, and maxillofacial surgeries.