Experimental Study Of BFGF-Collagen Sponge Promotes The Fibrovascular Ingrowth Into Porous Hydroxyapatite Orbital Implants

Objective: To investigate the effects of basic fibroblast growth factor (bFGF) collagen sponge and collagen sponge on the fibrovascular ingrowth into coralline porous hydroxyapatite (CHA) orbital implants.Methods: Forty-five New Zealand albino rabbits were divided into 3 groups randomly: group A,B and C, each of which has 15 rabbits. CHA orbital implants were implanted into their left orbits. The rabbits of group A taken as control group underwent enucleation with placement of uncoated CHA implants. The implants were implanted after coating with collagen sponge and bFGF-collagen sponge in group B and C respectively. The rabbits were clinically examined for inflammation and implants exposure every day after implantation. 9 rabbits ( 3 in each group) received technetium bones scan at 2,4,6,8 and 12 weeks postoperatively, in the mean time, the implants were exenterated for histopathological examination. All of these examinations were taken to compare the difference of the three groups in the degree of fibrovascularization of the implants.Results: 2 weeks after operation, the implants of group A presented little fibrovascularization. Group B and C were only fibrovascularized at the periphery in different degree; the difference of technetium bones scan between every two groups was significant (p<0.05 between A and B, p<0.05 between A and C, p<0.05 between B and C). 4 weeks after operation, every group showed higher degree but incomplete fibrovascular ingrowth; the difference of technetium bones scan between every two groups was significant (p<0.05 between A and B, p<0.05 between A and C, p<0.05 between B and C). 6 weeks after operation, the implants of group C demonstrated complete fibrovascularization; the others were higher than that of week 4, but fibrovascularization didn't extend to the center of the implants; the difference of technetium bones scan between every two groups was significant (p<0.05 between A and B, p<0.05 between A and C, p<0.05 between B and C). 8 weeks after operation, complete fibrovascularization of the implants of group A and B occurred; the fibrovascular rate of group C didn't change in comparison with that of week 6; there was no significant difference of technetium bones scan between every two groups. 12 weeks after operation, each group showed few changes in comparison with that of week 8; one implant of group A exposed at 3 weeks and presented little fibrovascularization only at week 12 postoperatively.Conclusions: 1 )Both the collagen sponge and bFGF(20μg) -collagen sponge could promote the fibrovascular ingrowth into CHA orbital implants. 2)The collagen sponge promotes the the fibrovascular ingrowth into CHA at early time after the implantation, but doesn't shorten the time required for complete fibrovascularization of the CHA implants.3) The bFGF(20μg) -collagen sponge promotes the fibrovacular ingrowth into CHA at any time and has stronger effectiveness than that of the collagen sponge, as well as shortens the time required for complete fibrovascularization of the CHA orbital implants.