Pregnancy Outcomes In A Sprague Dawley Rat Model Of Periodontal Disease

Periodontal disease has been linked with preterm, low birth weight babies. However, results of epidemiology studies conflict. An animal model is needed to test this relationship. We propose that periodontal disease in rats would result in preterm birth. Periodontal disease was induced in female Sprague Dawley rats by tying 5/0 silk suture around four molars, one in each quadrant, at least 30 days before the rats became pregnant. In addition to the silk ligatures, the oral cavity of a second group was inoculated with live Porphyromonas gingivalis (ATTC 53978). The control group had neither ligatures nor P. gingivalis . After birth, the jaws of the dams were x‐rayed and bone height measured as percentage of the tooth height. Ligatures reduced alveolar bone height in rats (0.48±0.05, p<0.01) compared to controls (0.055±0.03). The combination of ligatures and P. gingivalis further decreased bone height (0.39±0.08, p<0.0001). In this experiment with Sprague Dawley rats, periodontal disease did not affect birth outcomes, including length of gestation, and number and weight of pups. Supported in part by Research Grant No. 21‐FY1251 from the March of Dimes Birth Defects Foundation.