The purpose of this study was to evaluate effect of platelet rich plasma on the treatment of Grade II furcation involvement, with Demineralized Freeze-Dried Bone(Dembone®) and bioabsorable membrane(BioMesh®) in humans by digital subtraction radiography. 12 teeth(control group) were treated with Demineralized Freeze-Dried Bone(Dembone®) and bioabsorable membrane(BioMesh®), and 12 teeth(test group) were treated with Demineralized Freeze-Dried Bone(Dembone®), bioabsorable membrane(BioMesh®) and Platelet Rich Plasma.

The change of bone density was assessed by digital subtraction radiography in this study. The change of mineral content by as much as 5%(vol) could be perceived in the subtracted images.

The change of mineral content was assessed in the method that two radiographs are put into computer program to be overlapped and the previous image is subtracted by the later one.

Both groups were statistically analyzed by Wilcoxon signed Ranks Test and Mann-whitney Test using SPSS program (5% significance level).

The results were as follows:

1. In test group, the radiopacity in 3 months after surgery were significantly increased than 1 month after surgery(p<0.05). However. there were no significant difference between 1 month after surgery and 3 months after surgery in control group(p>0.05).

2. In test and control group, the radiopacity in 6 months after surgery were significantly increased than 1 month after surgery(p<0.05)

3. In test and control group, the radiopacity in 6 months after surgery were significantly increased than 3 months after surgery(p<0.05).

4. There were no significant difference between test group and control group at 1 month, 3 months after surgery, but radiopacity in test group were significantly increased than control group at 6 months after surgery(p<0.05).

In conclusion, Platelet Rich Plasma can enhance bone density.