The purpose of this study is to evaluate the effect of methylprednisolone on the healing process and the effect on the contact surface of Medpor and bone after administering the methylprednisolone, , and also the effect on the elapse of time in healing and on thickness after implantation of Medpor.
In this study, the middle part of the rat skull was exposed and Medpor was placed under the periosteum; the diameter : 8 mm, thickness : 1.5 mm (thin) and 4.5 mm (thick). Then coverage of the periosteum was performed. After the administeration of methylprednisolone, the light microscopic and scanning electron microscopic examinations and hardness measurements were performed after 2-, 4-, 8-weeks implantation.
The results of this study were obtained as follows :
1. The inflammatory responses of the control group and the experimental group were reduced over time, especially of the experimental group. They almost disappeared at 8 weeks after surgery.
2. In light microscopic examination, 1.5 mm implants responded better than 4.5 mm and osteoid formation showed a slightly at 4 weeks after surgery. It showed increased findings at 8 weeks after surgery and the experimental group showed slightly decreased findings compared to the control group.
3. In scanning electron microscopic examination, a large number of osteoblasts came up through the observation, inflammatory reactions disappeared faster in the experimental group than the control group. The arrangement and the amount of deposition of bone matrix over time in the experimental group was more irregular and reduced than in the control group. These findings were more remarkable in 4.5 mm than in 1.5 mm. The fibrous connective tissue was shown in the thicker implant rather than the bony tissue.
4. In hardness measurement, bone adjacent to Medpor showed a statistical difference in the hardness depending on the time, the thickness, and the use of methylprednisolone : Hardness . - was decreased over time and in the thicker implant, and the use of methylprednisolone (P<0.001).
It is concluded that the methylprednisolone is considered to suppress the inflammatory reaction, however, it could delay the wound healing because of the inhibition of osteoblastic activity. So, the use of methylprednisolone should be restricted except serious inflammatory response after the operation.
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