抄録
The process of remission after CO2 laser irradiation of the rat jaw bone was assessed using an X-ray microanalyzer in comparison with dental bur holes, and the effects of the CO2 laser were studied. The following results were obtained:
1. A comparison of SEM of changes after laser irradiation revealed a convex profile with degeneration of the bone at the margin of the defective site. There was a slightly depressed area of bone fusion between the bone at the margin and the bone at the distant site for 15 days immediately after irradiation, although the defective site presented only slight new bone generation even 45 days after irradiation and was still surrounded by degenerated bone; the most of the site was covered with irregular, newly generated bone.
2. As a result of a comparison of analyzed line images among the laser groups, the X-ray intensity for Ca and P reached a maximum at the margin of the defective site immediately after laser irradiation, and the intensity transiently decreased at a site ca. 50μm distant from the defective site. The X-ray intensity at a distant site ca. 100-300μm away from the defective site was equivalent to that in the non-irradiation group, but it increased 3, 10 and 15 days after irradiation. Irregular line images associated with new bone generation at the defective site and its periphery were obtained 45 days after irradiation.
3. Secondary electron images taken from the group given dental bur holes showed a clear marginal border around the perforated site immediately and 3 days after perforation. Newly generated bone was observed at the margin of the perforated site 10 and 15 days after perforation. On the 45 th day after perforation the perforated site width had narrowed.
4. Analysis of line images revealed an X-ray intensity for Ca, P and Mg which was the same level as that at a site distant from the perforated site, even at the margin of the perforated site, immediately and 3 days after perforation. The pattern of the intensity changed in a wave-like form for Ca, P and Mg, over an area ranging from the margin of the perforated site to the perforated site 10 days and 15 days after perforation, suggesting new bone generation. The width of the perforated site further decreased and the pattern in the vicinity of the site was also unstable on he 45th day after perforation, although the wave form was similar to that of a healthy bone.
