Histometric evaluation of periodontal bone loss in rats. I. The effect of marginal irritation, systemic irradiation and trauma from occlusion.

The effect of marginal irritation, trauma from occlusion and total body X-irradiation on interradicular bone of Wistar rat molars, was studied after an experimental period of two weeks. Histologic findings and slatistical evaluation of histometric results indicate that: –  the only single factor capable of reducing the height of interradicular bone was marginal irritation, –  the only additional factor that was capable of increasing this reduction in height was total body X-irradiation, –  marginal irritation, either alone or in combination with trauma from occlusion increased bone density in the submarginal areat –  total body X-irradiation inhibited the osteogenic reaction induced in the submarginal area by marginal irritation. –  trauma from occlusion did not have any effect on the parameters measured.