Evaluation of porous vitreous carbon or silicon implants by radiology in rat's skull.

PURPOSE Evaluate by CT the use of porous vitreous carbon (PVC) and silicon (S) implants as the replacement bone in the craniofacial skeleton of rats. METHODS 40 rats divided in: Group A (n=20) PVC submitted to the implant of a fragment in skull. After the euthanasia, the animals were divided into two subgroups: A I: 10 animals, studied in the 7th postoperative day (P.O) and AII: 10 animals, studied in the 28th P.O. In group B, S, 20 rats were submitted to S implant in the skull. All other steps were identical to group A, with designation of subgroups BI and BII. CT with beams in axial cuts of 1 mm thickness to obtain 3-D information. It was used Hounsfield scale for evaluate the radio density of the implant. They were used non parametric tests to analyze the results. RESULTS The 7th PO boss remained in the two groups, but for 28th PO, observed reduction in the volume of the implant in Group A, not observed in group B. CT studies noticed different radio densities around all of S prostheses (pseudo-capsule), that don't appeared in CPV implants. The S has remained unchanged in the CT, but the CPV has had a modification in its radio density (p< or = 0,05), in all implants. CONCLUSION In CT evaluation the implants of CPV have greater deformation that the S, which makes them not suitable for replacement of membranous bone in the rat skull.